I would look into either a kabota or toro outfront.I have not owned any of these machines but I know a couple of companys that do.These machines are fast strong and reliable.I think if you are going to invest in that big of a mower,than at least look into or demo one of these mowers.
Well I think it goes without saying I would give ANY John Deere product my full endorsement. A couple of things: Since you didn't really say what size of yards or the size of the properties you will be mowing I will give you a couple of suggestions. If you are mowing very large and wide open places ie. apt. complexes, schools and retirement homes and have the money then you could go with any of the series larger than the 725 with a 60 - 72 in. deck or even the 1100 series tractors which come with a 72 in. deck, but you better have the money. However, let me tell you what we use. We are getting the new Mid Z-tracks in March. If you are not familiar with the Z-Track series they are similiar to a grasshopper and have the decks out in front. The new Mid Z-Tracks have the deck set back (thus the name MID) and are almost exactly the same as the Lazer Z only green. They have a 25 h.p. Kohler engine with a 7 gauge iron deck and give a great cut and are excellent on hills. We mow over 100 accts. per week and use are riders on about 70% of them. Our largest acct. is 17 acres. With the two Mid Z's on the job it will take us about half the time from what we use to have which was the John Deere 710. With any John Deere product, you are buying quality. If you really want to be sold just go to your local J.D. dealer and ask to test drive something. If they won't let you then I guess they don't want your business. I'm sure they will though. If you have any other ?'s e-mail me at firstname.lastname@example.org.
Sorry, forgot to answer one of your ?'s. The cons against some of the front deck mowers are that they aren't the best on hills. Other than that, I love the floating deck on the 700 series and the Mid Z's that I was talking about does not have that. Also, and here is the biggest con in my opinion, most all John Deere mowers except for the Z series have side baggers which in my opinion are terrible! If you are just cutting then they are great, but if you have to bag then I would definently look at the Z's because they have the rear dump system.