Actually the bagging/mulching changeover on the LB 10323 and 10550 is a lot more trouble than the current rear-discharge mowers. It is true that the LB had a huge leaf bag available. Here's what I do; first, I keep up with the leaves, never letting them get thick before I work the yard; then, I'll usually mulch the whole yard, then go over it with the bag on. This is a win-win because the lawn gets some of the mulching benefits (about half the leaf material stays down in the grass) and you get a clean-looking, bagged lawn. The bag holds more because the leaves are chopped up, and you cover more ground before having to empty. The chopped leaves you bag can be placed directly into mulch areas, where it turns into soil about ten times faster than unchopped leaves.
Incidentally, why do you have to bag all your leaves?

As of this year, the city is discontinuing its use of vacuum trucks. I used to be able to blow them all up to the curb in huge piles and the sucker truck would get them, but no more. For the past four or five years, I made quick work with the LBs. I have been collecting leaves steadily, but it's been a real pain to get my mowers running right.

In my experience the rear bagging Toro Super Recycler will either bag or mulch leaves exceptionally well. The deck, chute and bag designs are well thought out and they chop and mulch or bag masses of leaves very well. Just remember to empty the bag when full.

The LB leaf bag is awesome, and is probably the reason why I still use my Duraforce and haven't sold it due to its inherent design flaws and operator frustrations. The side bag attachment is the best of its kind...its super huge opening and it is located in the optimal spot for the best discharge. I totally love my LB leaf bag.

I am probably going to retire my LBs except for leaf detail because they are so good at it. Not only is the bag huge, but the grate deal that keeps larger leaves in the blade longer compacts the leaves considerably more. I bought a Honda HRX and tried it out yesterday, and ergonomically it is pretty nice, but the Honda bag fills up very quickly and the leaves are not shredded nearly as fine. Now, if I can just get the carbs working right...

I want to second what Saxman1 says.

I have tried a number of different ways of cleaning up leaves and found that going over the lawn once with the mower in the mulching mode and then going over again with the bag on works great. The results make great mulch (unless you live in a real hoity toity neighborhood).

Randy