I have 2 JD 300's, and I pretty much live on them all summer. I've not bought a zero turn because we need to have more than one, and everybody says I'll never use the old kind once I get a taste of the zero. Buying two at once is a big decision.
I usually mow (chop) the leaves to bits before bagging or I'd only get about 20 feet before I need to dump. If you are going to make just one pass, get a leaf blower and blow the leaves far enough away from obstacles to get them under the mower deck. I did have a power baggger, but it was insanely cumbersome. I have no problems with a simple air-flow bagger as long as I use high-lift blades. When I have an area where I don't want to pick up, but will need to start picking up again pretty soon, I just remove/replace the chute base, not the whole nine yards. If I were you, I'd just get a bagger for the smaller machine, and use the zero for mowing and leaving the clippings lay. I see the bag assemlbies occasionally on Craig's.
Just like the last 2 or 3 years, I vow that this will be my last season of full-time mowing... I did get a couple from town to mow the smaller place once last summer, and it cost me $275 for a pee-pee poor job. A good job for both places will certainly be more than $500 per week. Tough move to make...
The first mower is a little 324 (I think) tractor style 48" deck. It would take me a week to mow the place (we have fields). My dad took pity & got a residential zero-turn Z535M, also a 48" deck. You are correct - if you ever get one, you won't go back to the other; however, the zeros are SO much faster, you'd cut your mowing time in half, if not close to it. Every time we went to JD & they asked me how much I was cutting with the residential zero & I told them 10 acres, they would tell me "you need a commercial mower". Dad bought a commercial model Z920M ZTrak summer before last - it is much larger (60" deck) & boy, it rides SO smooth compared to the other two & of course, it is a dream to steer. I have 3 issues - gas tank opening is a bit high (I have to use a step ladder) & the hole is very small - had to get a funnel with a very narrow tube to fit down in there. The back tires are so wide, when I do a zero turn, they will leave a bald patch, especially if the ground is soft from a rain. Other than that, I am glad we got the bigger mower. If I start early, I can actually do the place in a day, staying on the mower all day except for lunch & bathroom breaks. I usually do it in a day and a half. BTW - we sold the Z535 to a relative - they love it.
The "stable" from left to right: Little Buddy, Zero (the 'racehorse' - very fast!) & Clyde (the work horse like a Clydesdale).