The 5455 is a great tractor. Yes, I'm the guy who got a dud, actually 2 duds(a 596 and a 5455), but the one I have now has been great so far. Baled hay with it most of the summer. The 596 had tranny and hydraulic problems, and the first 5455 had fuel injection problems. The dealer bought it back and sold it to me when he bought back my 596. Luckily for me I had it on a 2 week trial and was able to refuse it and get a new one instead. I still believe that both tractors would have been fine if the dealership had a mechanic that would be concerned about fixing it instead of just slapping something on it and getting it out of "his" shop. I no longer do business with them BTW.
My only gripe so far has been the spacing on the loader mount making it difficult to reach the oil filter(my Montana is the same way). Would it really have been that difficult to make the loader and mounts a couple inches wider?
All in all though a very comfortable and dependable tractor though.
I just bought one after looking at several. The hub seals on the 42/43/5400 and matching Challenger models seem to last 1500 hours or so. The one I bought had a timing gear update kit, a wiring harness update kit and a few other things.