My gut feeling is you are going to regret getting an electric mower. This is based on the following observation all taken from your post.

1. Your large is quite large, and may be too large to cut the whole yard at one time with an electric.

2. The self-propelled feature will reduce the energy in your battery requiring more frequent charging.

3. You said your yard is hilly. The extra power needed to move the mower up the hills is going to further detract from the available energy in the battery, requiring additional charge time.

I have a large yard, and faced with similar requirements as you, I went for a John Deere E130. and do the trimming with a good string trimmer with brush cutter attachment.

What ever you get, make sure that i can pull a small trailer, something that is nearly required for a large yard.

kr, these are valid considerations; however, it seems the walk behind mower is only for the places where the riding mower won't go. Still, it could be too much for one battery load on the EGO. I mowed about 6,000 feet of hilly at the other house. There were days when the grass density sucked the power, and I could not finish on one charge. Having two extra batteries to fall back on worked every time. The backup batteries were smaller in capacity, but usually there was only a few hundred square feet left to do.

EGO also has a zero turn mower available for your future consideration.

Another thing I like about the EGO is if I do need to recharge a battery, I probably need to take a break anyway, and the batteries recharge in 40 minutes.

On the CON side of things, if you need to get it repaired, which I did, they had to ship the unit to Atlanta for 10 weeks. That's a lot of grass going unmowed. I borrowed a neighbor's mower. The problem I had was this. The EGO has safety switches to ensure it is set up properly before the motor will start. For example the collapsible handle has to be fully extended, the handle has to be in one of two positions for pushing, the green start button has to be pushed, and then the bale handle pulled back. The wires they use to send those signals are not that hefty and don't seem to be perfectly protected from moving the handle from operating to storage mode. Anyway it seems to be common (according to the Interwebs) for one of those wires to break. You can bypass any or all of them, or you can take it to the Home Depot (at the time) Rental office and they will ship it off. Before you buy any electric mower you should check how you get it fixed when/if something goes wrong. Oh, and I have a friend in the lawn mower repair biz - he looked at it and decided he could not diagnose it.

And I just remembered something else...this is my original EGO mower. The mower that broke was a Black and Decker which broke from my wife hitting a rock so hard the plastic deck broke. But also I did buy an EGO without the self propelled feature for my sister in law. She's at the beach with a perfectly flat lawn and is fine with pushing it. Would I buy another EGO? Absolutely yes.

That is why I bought a John Deere, Parts and service are always available at your local John Deere Tractor dealer . I had to replace the front bumper on my 20 year old JD lawn tractor. I went down to the store picked it up and installed it. Was back on the lawn in about 3 hours, including travel time to and from the store. While this local store does not service the range of JD equipment, in our previous home, the JD dealer did. It was an interesting experience buying parts for my lawn tractor, and the customer next to me was buy parts for his huge combine.

I have a lot of things to say about my Ego mower, mostly positive. I bought it because it is easily available "locally" and is part of a system. The store was having a sale and on display were three self-propelled models, with the middle one on sale for the price of the lower one ($599). It works fine, I really like the feature that you can run the self-propelled function and the mowing function separately. I have a very hilly field to mow, and I can use the self-propel feature to get back up hill over the already mowed area without the blade running. One complaint I have is that if I'm mowing with the self-propel and stop, it doesn't disengage when backing up. I solved that problem by releasing the self-propel button just before I stop. I never run out of battery before I run out of personal energy, so battery life is not a problem. I am annoyed at the noise the charger makes when charging, but when I get my garage built, that issue will go away.

I was looking at some of the other Ego tools, but they use smaller batteries than the mower, so that's a disappointment (but I wouldn't want to run my chain saw with that heavy battery anyway). My next tool will be a snowblower which, I hope, will use the mower's battery.

Regarding repairs - I don't actually how to handle that, because my dealer doesn't do repairs. My John Deere riding mower has a similar problem - I haven't found a local dealer, just some "small engine repair" places which don't have easy access to parts. The nearest JD dealer is over an hour away in another state!

Last month, I was having trouble deciding on which electric lawn mower to purchase. My friend suggested the Cubcadet, so I ended up buying it. It's been working really well and I have to say, I'm really happy with my purchase. I would definitely recommend the Cubcadet electric lawn mower to others.

Markku, the video you linked to is very nice, except that he only mowed going up or down hill, which my JD does fine. It's going across the slope that is a little dicey with the JD. If it's too dicey for the riding JD, then I use my new Ego self-propelled, which I really like.