The biggest lesson that I (and my dealer, and NH) learned is that you need a LOT of rear-end counterweight on the thing to use your FEL effectively. Since I have put on the wheel weights I've moved another 300 yds of gravel in 4wd all the time and have had no problems.
New Holland says you need to make sure you always have at least 20% of your overall loaded weight on the rear tires; if this is the case the tractor will be fine. Note that this is only true for NH tractors simply because they have more powerful hydraulics and heavier duty FELs than other comparable tractors of similar HP and size.
Yes, I had a lot of trouble... BUT it was a learning experience for all involved... NH and my dealer learned along with me, and they were both there for me in the end. I am totally pleased with my investment.
Note that I work my 55 VERY VERY hard. I've also become a very skilled operater and maintainer in the process. If you could listen to me working with the thing a year ago, you'd hear gears grind, engine stalls, lots of bangs... now all you hear is the purr of the diesel and never any indication of undue stress.
My 55 has more than paid for itself in just over a year. It looks and runs like new. I know it outperforms many tractors in terms of HP, hydraulics and price. I know because I did a serious amount of homework before I bought it, and because I had a Kubota 'Grand' before that just didn't cut it for me. JD was too expensive. No decent service nearby for MF... so NH was the best choice for me AND I like the color blue.
At the end of the day, all colors perform about the same (some are better at some things than others), and your dealer is going to make or break your experience.
Anyone who owns a tractor and has never had tractor problems is either lying or bought it for a lawn ornament.
Now make up your mind, buy whatever tractor you want, and get on with it. I'm looking forward to hearing all of your stories after a year of fun times on the thing.