I did exactly what you are thinking about doing 20 years ago, I moved from using all 21" units to a 33" Troy built. We thought we had gone to heaven, the unit worked great. There were a few problems with the pulleys being plastic at that time, and the durabiltiy of the deck wasn't good. And we had to upgrade the handle mounts. But I would guess they had plenty of time to correct those problems. The electric start was nice. Since the unit doesn't drive from both wheels you have to put some torque on unit to keep it straight when on hills. All in all we like it. Is it a lot less than Scag 32" belt driven? The Scag would be a lot better or some unit like the Scag.
I have had a Cub Cadet(about the same as the troy Built) wide cut 33" since 2000. I haven't a clue how manyhrs are on it but I'm sure there is quite a few. Runs excellent but the 9hp Briggs does use some oil. The only major thing that has happened is I had to replace the shift fork in the transmission this year, mostly my fault though. Mulches leaves and bags really well better than my JD ztrs. Definately not a commercial piece of equipment but it does have an industrial engine. Would I buy one again, maybe, just depends on who is going to be using it, with employees definately not.
Iv'e been thru a couple 33" widecuts over the years, wouldn't be without one! Other than loosing a spring pin or 2 on mine and having the engine mysteriously not start one day, requiring about a bigillion pulls of the cord to get it to fire up and running. It's been a fine machine!
I use a set of blades I "made" from a set that goes to a Bunton 36". I just use a pneumatic die grinder and made the center hole on the blade match the oddball hole on the original set of blades. Also have a set of Gator blades for fall I'm currently using. I have had zero troubles with these blades, the high lift ones have WAY more lift to them than the stock mulchers and bag and discharge much better. Suprisingly they also mulch much better as well!
Ok, I did have a failure a month ago, onl blade bolt came loose, and since they are "timed" blades they hit and it wasn't pretty! Ruined the blades, didn't bent anything, but the blades looked like I had been mowing large rocks! I'm sure I just didn't get the blot tight enough, and since I only have to sharpen them once every month or 2 it finally came loose...
Price brand new is $1,399 (recoil) and $1,599 (electric)
I bought a 36" LEsco belt drive a few years back, thinking it was going to be soooo much better than my troybilt. WRONG. That thing was like driving a walkbehind tank! Plus it was too big for the tight little areas I needed to use it in. Went back to the troybilt!
I've used the Troy-Bilt 33" for the last 2 years. I have had a few small problems with it...nothing serious though. Can't compare it to other similar size units as I've not tried the others. My local dealer carries these and he always gives me next day turn around and is only 2 minutes from home.
I like the way it handles and gives a decent cut. The few times that it was in the shop, I've had to use my Toro 21" Proline and was quite surprised how much I missed the Troy-Bilt. The front swivel casters makes it real nice for weaving around curves and such. But I also found that my cut times were not much longer when using the 21"??? Still prefer to use the 33" though.
Really like the height adjustment on the Troy-Bilt. You can change it to ANY height with a simple crank (not just 1/4" increments) and I even use my foot sometimes as I'm walking behind it (sometimes there are certain areas that need different cut heights). Overall, it's an okay unit but it is definitely not a commercial mower. I cut 50 lawns a week and have used it for 2 years and hope to get at least another year or more out of it. Keep it greased and change the oil regularly.