Also, the 3400 has a dual stage clutch. As you come off the floor the PTO engages first, then the drive clutch. It's possible to shift gears without disengaging the PTO, although I've not done that.
Unless you're getting a smoking deal on a 2800, I'd wait and see what the new model year brings. The economy L series has it's issues, I'm not bashing them, I own one.
The 3 point is jerky raising, no known 100% cure yet.
The PTO cables on the HST models is a weak spot. No such trouble with the gear models.
Clutch effort is high IMO, especially if you're going to be holding it depressed for a couple minutes. Hung pedals might be better ?
The diff lock lever on the gear drives is in a lousy location, under your right heel. Try pushing it down and working the throttle with your right toe at the same time.
The suspension seats stick sometimes, but that can be easily fixed.
Loader capacity is low for the size of tractor, again IMO.
I don't like the whine the HST models have, that's my personal preference.
No factory remote kit available, if you want rear hydraulics you have to piece them together.
I'd buy the gear tractor again, but it might not be a 2800/3400/3700.
Overall a good basic tractor, but with a few issues that Kubota hasn't addressed.