Good answers, lots of variety. For my money, I'd show the quote from Barlows to the local dealer and ask him to match it or at least come close on the L3800. If he can't don't burn your bridges since you'll more than likely be dealing with him for service and repairs no matter what you buy.
The L3800 for less money is more tractor in my opinion. You have the drawbar and suspension seat standard, not sure about cruise control. If you're mowing extended runs of field, you'll like the cruise. It's not essential, but a nice feature.
If you think you may EVER have use for rear hydraulics (wood splitter, power angle on rear blade, top n' tilt, down pressure for PHD, etc) get at least one set of remotes installed when you buy. It may be cheaper to install your own later as I did, but you need to be handy and understand hydraulics.
The suspension seat is 100% easier on your back. Mine was stuck when I got it, and I lived with it. It's freed up now, and makes traveling over rough ground much easier.
I agree on the 3 point hitch being jumpy, it's not perfect but is livable.
The L3400/L3700SU/L3800 are all 3 cylinder engines and relatively smooth. The loader damps a lot of vibration too, but your toes and fingers won't be "buzzing" at the end of the day in either case.
The L4400 is a very capable tractor too, more power, wider stance, bigger tires etc., as well as significantly more lift capacity on the loader and 3ph. Not really in the same class as the L3700 or L3800.
Sean