I don't have input on the Contender but do on the Citation XL and the ZT2500 as I have both.
The Citation XL I have is a 27hp 61" mower deck with about 100hrs on it. We bought it last season to replace the Ford 1900 with a 72" mower deck that was overkill for our 4 acres of grass cutting. It was simple too much for what we needed. And the wife would not run it. The XL has been very easy to use and cuts our combination house grass and field grass well and is a very even cut considering it's 61" across. If I cut sideways on the hill, sure it's high and low just due to the weight on the lower side of the deck but over all it's great on hills with the very wide tires it has and hasn't been any problems to cut my hillsides. It does cut fast just because I run it full speed across the fields even on bumpy sections due to the full suspension front and rear. This gives a tremendous cut speed advantage compared to any other mower. Not many can do that at 10mph. Even the ZT2500 throws you around too much. This one has very heavy duty ZT3400 transmissions so it's good that way. (shop for transmissions first is the moto in ZTR's and i agree 100%). I have no complaints. Want to see the cut from it ? Here's a link to my front yard.
http://www.lhsc.net/microseven/fileimage.jpg
As for the ZT2500, I bought it about 5 years ago now. It has around 375hrs on it and has been ok. It has front suspension only and has 24hp with a 48" fabricated deck (both have them) with Gator blades installed. (Helps a lot with the cut on higher grass I've found) This one has the ZT2800 transmissions on it and i've changed the oil and filter in it twice now. Synthetic helps a lot on these transmissions to keep them smooth running. Both Transmissions have replaceable filters. A good thing you would want to get IMO. I can cut pretty fast with this mower but it's top speed is around 7mph so not as fast as the other one. And it does bounce around a lot in the field areas where it's just plain bumpy so slower is better but takes longer to do the job.
As for the Gravely, I don't have any experience with them other than my dealer carries both. He says the parts for the Gravely are very expensive. That was his only comment as I looked at them in the showroom last spring. REliability wise I would expect both to be similar as they mostly use parts from vendors like Kawasaki and Briggs and Stratton and Hydro Gear. I've only had one repair on the ZT2500 and that was a cracked bar that holds up the mower deck. I think from all the banging around in the fields with it broke it. Twice. The 2nd time I took it to a welder and he braced the crap out of it and it's been fine since. I think it was just a weak link since the mower deck is so heavy duty that banging over the moguls just broke a weaker asm. It's been fine since the weld two years ago now.
One thing I've found is that lowering the tire pressures helps a lot with traction and ride quality. By going from a rated 19lbs in the rear (bigger tires) to 10lbs it makes a big difference. Leaving the front ones at full pressure keeps them from getting flats easier I've found too. So they run at 25lbs. Just something that was interesting I found along the way.
Your call. I think both are good machines but if you have a bumpy, lumpy field like i do and want to cut the grass cutting time down, you can do that with full suspension at 10mph. It's pretty amazing and brings a smile to my face every time i rocket across them.
Steve
