I have owned 4 front mount grasshoppers. They are great. I currently have a 725 with a kubota gas engine, 52 inch deck, electric lift. I also have a mid mount. I would rather run the front mount any day. The only thing I would do differently is getting the Diesel engine, but this one was such a bargain I couldn't pass it up. It is plenty powerful and purrs like a kitten. I live in the south so I did install a five blade fan that really helps with the cooling.(i don't have to clean the screen as frequently)
Uh, sorry, I just saw this post...a couple years late. I know them intimately well.
Actually I'm down to just matching "his" and "hers" front mount diesel 700 series Grasshoppers. Back when I had a mowing business I also had two 900 series front mount diesel Grasshoppers. The only issue with the bigger 900 series and the 72" decks is that, at least in my case, I seemed to scalp a lot of areas with that wide of a deck and was limited getting between trees. IMHO, the happy medium is the 61" deck. Also, having had a 4XXX series JD tractor with a 7 Iron mid mount mower at the same time, I can tell you that the deck on a front mount Grasshopper is almost exactly twice the thickness of JD's highly promoted '7 Iron' decks.
It's funny that I just saw this thread the day after I had the first problem with any of my Grasshoppers. I started mowing yesterday with my 1999 model (2260 hour) 721D2 and I suddenly smelled diesel fuel. I looked behind me and when I crossed the driveway, I saw a trail of diesel fuel.

Never had that happen before. I immediately shut it off and used some slings under it and picked it up with my JD 5525 front loader (IMHO, the best tractor ever in the under 100 hp range, and I've had several dozen) and carried it back to the barn to work on. It turns out I had an Oak branch pull the hose off of my fuel filter. That was actually 2 good things; first, it couldn't have happened very long before I noticed because it was just running on the diesel in the hose and second, that keeps the streak of "
zero repairs" of any sort intact since 1999 and over 2000 hours.
I tell ya, the two 700 series front mount deck Grasshoppers are the first machines I've ever owned that are tougher than I am. I've gotten pissed after mowing in the hot sun for hours and having those pecker gnats swarming around me and just ran the machines as fast as they will run (about 11 mph) across areas so rough that I couldn't stay in my seat and the bumps blurred my vision they were so hard and I've still never broken anything. My only key is that I've never, not even once, run more than 8 hours (about how long an 8 gallon tank of fuel lasts) between greasing all of the fittings. I've mowed hills so steep that I couldn't walk on them and bounced them mercilessly and they keep on ticking.
This last winter I was thinking that 2000 hours was a long time on a mower deck spindle, so I took one off and put my calipers on them to compare to what new specs were. Much to my surprise, after that many hours, I could not come up with any measurable wear!! I'm still on the original deck belt, original tires etc. The only thing I've changed has been the filters, fluids and mower blades. I've hit rip-rap using them as 'bush-hogs' in areas that were grown over and couldn't see what I was going over. Knocking one side off of a blade sure makes a mower vibrate like crazy! Still, just sharpening the blades a few times every year I get about 250 hours or so out of a set of blades. Although they cost more, it seems that the Grasshopper brand of blades last much longer and will hold an edge far longer after being bounced off of the ground hundreds of times.
Now that I've said that, I'll end up with my first issue. Still, after 2200 hours on the older one, I really wouldn't feel that the mower owed me anything if it had something break. They
definitely have not been easy hours nor over areas like a golf fairway. I have owned JD, Kubota, Exmark, Scag, Ferris, Great Dane (the former owner of Scag's new company after he became infuriated that the new - about 10 years ago - owners of Scag really dropped the quality of the machines to have a higher profit margin) and a Dixie Chopper mower. I didn't own one, but probably the worst (sorry if it upsets someone) quality ZTR I've ever worked on was a Cub Cadet 'Tank'. I don't see any around anymore, so it's probably safe to tell that they were totally junk; even far lower than the (admitted residential) Dixon ZTR mowers, and the Cub Cadet machines were advertised as "commercial" models and not sold in box stores (probably because the box stores do not have full time service departments to start working on them after they first start them).
Since I've had so many and have worked on several others, I feel that I can give an honest opinion on the build quality, durability and mowing quality of many ZTR mowers without any prejudice. I just kept the Grasshoppers because they were totally trouble free and the front mount design allows them to ride better than even the Ferris ZTR mowers that have 4 wheel suspension. And, BTW, Ferris does make a very, very good mower. Their build quality is very much like a Kubota but has suspension.