Back to the edge... pay close attention to item #2.

Repost of Slammer's Rules...

1. Carefully evaluate the size mower you need and buy at least one size larger.

2. NEVER buy a mower from ANYPLACE that will not let you test drive it or at least a similar model. Ergonomics are just as important as performance and capability.
(Vitally important!)

3. DO NOT base your purchase on price or brand name alone! Do proper research and find all of the available models that fit your criteria and haggle, save, or trade to get the right equipment for the job. Do not compromise!

If you follow these three tips you will end up a happy camper with just the right unit for the job. If you disregard this advice your gonna end up with One or the other of the following problems:

A. Buyers remorse. Stuck with a piece of junk or simply a unit inadequate for the task at hand.

Or..

B. A teed off spouse when you start shopping for another tractor just 3 - 6 months down the road because you didn't buy the right unit in the first place.

Now go forth and shop and try and have fun!

I personally prefer new over used as you know what you are getting. The x500 is a lot of tractor. Its expensive but its impressive. The rear tires are HUGE. The 25hp Kawi is also probably the best out there. K72 with traction assist is unbeatable. No more leaning to one side of the tractor when a tire starts spinning. Accessories up the wazoo. The JD company is also nice to deal with. When you call them you get an english speaking person that knows what you are talking about. My advice is simple. The cost of underbuying is greater than the cost of overbuying. You will absolutely never regret getting the better model. Lastly, the resale value of a well maintained JD GT is very impressive. Not that you will be in the market to sell it but it feels nice knowing that.

On the scalping turns, I think there are a lot of adjustments you can make to eliminate or at least minimize those types of problems, including adjustment of the anti-scalping wheels on the deck...that's why they're there. Also close attention to the deck suspension adjustments so that there is an even distribution of the deck weight all around.

I have a little experience here because I have a JD 425 EZTrak ZTR with the 48-in. deck and Power-Flo bagger system. That Power-Flo places a lot of weight on the right hand side of the deck and I had to carefully readjust things in order to eliminate the RH dip-down problem. It cuts nice and level now. BTW, I installed the bagger system myself and saved $50...which, looking back now, is actually a bargain because there are a fair amount of fitment issues involved. The dealer told me he loses money on every Power-Flo bagger install. I believe it.)

I think that with consideration of the X500 series, I'm already obeying the "Buy one size larger" rule. Problem is, once you decide to consider the next size or model up, where do you stop? X324 begat X500, then used X534, and then used X540. I've even looked at a couple of used X724s, but I think that with all my low hanging pine trees and the higher seating, I'd run into problems, at least for mowing, which is most (but not all) of what I do with the tractor.
As for Slammer's Rule #2 - I don't disagree - I just don't have dealers around here with much room for test drives. I'l need to ask again.
Larsol, you make a good point on the deck adjustment and the RH Powerflow dip-down issue, as the pattern I mow in usually put the PowerFlow unit in the downhill position. Hopefully that issue will be eliminated with my next purchase.

I own a x534 with 48" deck and love it , The mower does more turning than staight line mowing . This mower shines on landscaping cut trimming in half. I only mow 3/4 of an acre and it is a full 1 hour and a half job, going around smaller trees I still have to back up. I turn and turn and turn ABSOLUTELY NO SCALPING , if it would have happend DEERE WOULD HAVE GOT IT BACK...You should not mulch if you dont keep up with your lawn. BE CAREFUL BUYING USED EQIPMENT...it could be possible the 54 could have this issue and dont undersize your deck everytime you mow you will *&%#@

You said your dealer is a small one so I don't know if they would do this but my dealer brought the two mowers I was considering out to my property for test driving on my conditions. Also, with the larger deck the wider overhang past the tires allows you to trim closer to things in my opinion.

What stop me from buying a x500 was no power steering,no tilt wheel and most of all no hydraulic lift for all those attachments,try using that foot pedal with a 350# snowblower

You can steer the x500 with one finger.
As far as the tile wheel--what can I say
Hydraulic lift? Its really not that bad w/o it.

Now if you mentioned 4 wheel steer, that I can understand.
Or possibly the water cooling.

1. Quality of cut
2. Mulching capability
3. Quality/Durability of transmission
4. Agility

Why are you not considering a ZTR?

Thanks for all the insights, guys. Much appreciated.

I'm considering a ZTR because driving in and through my spruce trees on one, with all the low-hanging branches, doesn't sound like much fun. Plus (and please correct me if I'm wrong), my options for uses beyond mowing are extremely limited .

I had a chance to stop by my local JD dealer today. He had an X534 they were prepping for sale outside, and I was able to drive it (around a very small parking lot). I've got to say it was a bit weird at first, turning the wheel & feeling the rear end rotate out from behind you. I've only heard of the AWS uneven cut complaints from a couple of people - everyone else I've heard from that actually owns an X534 really loves it.

I wish I could've done a direct comparison with the X534 by driving an X500 or X540, but they didn't have any outside the showroom (the midwest this ain't). I wish my dealer had a used tractor inventory, as I'd have no problem buying used from him, but they don't sell used equipment or take trade-ins, so, based on my budget, I'll only buy new from him if it's the X500. I'd LOVE if they'd consider brining two machines out to my property to test ride on my own conditions, and I'm sure they would if they had an inventory of slightly used recent models, but they only carry new machines. It might also be different if I were going to buy from him no matter what model it is that I decide on - but I can't honestly say that.

Although I asked, the dealer apparently can't explain the seemingly contradictory spec that shows the X534 having a larger turning radius than the other X500 series tractors (albeit leaving a smaller circle of uncut grass). I did get the sense that the AWS, with a 48" deck would come in plenty handy with all the things I mow around in my yard, though - so at this point it probably comes down to cost (x500) vs. manueverability (X534) vs. longevity (liquid cooled) and flexibility (X540, or X335).

I still wish there were a better option than the PowerFlow bagger, but I do have to say that the newer Power Flow units I saw had a very simple bar guard mounted on the deck - really just an "L-shaped" piece of rod - but the rod takes the bulk of punishment from trees instead of the bagger housing. Pretty primitive, but probably effective. The PowerFlow manual for my Scotts doesn't make any mention of a guard. Should've thought of that one myself.
I'll likely talk to a couple of the used tractor dealers over the next couple of days, and then make a decision.

Which tractor was the winner?

An important note is that the X300 series has a 4 year/300 hour warranty for a new purchase, whereas the X500 series has a 4 Year/500 hour warranty. If you're running more than 75 hours per year, the additional warranty may be an important factor.

I got an X520 in early 2008 and have about 100 hours on it. I got it primarily for the 54" deck standard, the longer warranty and the liquid cooled engine. I have over 3 acres, about half of which is pretty rough, with a decent slope. The X520 does the job with power and agility to spare. The cut quality is very good (keeping in mind that I tend to cut high, 3.5 to 4 inches, and keep my blades sharp). I've had no issue keeping a level deck, either. The transmission is solid, and is a huge step up from the one I burnt through on an L120 a few years back. I mow, dethatch, aerate, pull a cart and spreader without any issue and, with the rear wheel lock feature, have never gotten stuck. It's a pricey beast, especially new, but so far, my opinion is that I would buy another one, hands-down. That said, I intend to keep this one running for a long time.

I agree with those folks that say "buy one model up from what you think your needs are." I went in looking at the X300s, but bought a X520 and am so glad I did. I now covet the X540, but it really wouldn't have been work the extra ~$900 for my purposes.