I bought an Exmark last summer. Best machine I've ever mowed with. I can take a 15 degree hill w/ no problem (although I do add quite a bit of ballast to it
)...You won't need to bag. The suction of the deck and the fine/even clippings (even WITHOUT the mulching kit) is wonderful. I tried many of the ZTRs before I bought the Exmark. Very pleased with my purchase.
EDIT: as you check out the various units, be sure to check the quality and assembly of the frame & deck. Many are cheap stamped steel. I prefer a heavy duty welded deck. Ask commercial mowers and municipal systems what THEY use. The magic is in the high vaccum of the deck. You'll want a foot-operated deck raise system and be sure to get one that you can service the hydraulics on. Many of the cheaper ones can not be worked on, but replaced in huge assemblies.