55's had more hydraulic PSI. 2530psi over the 2250 in the 30-50. Guys run vacuum 12 row planters with 4440 all the time, so they will have decent flow.   If it's in your budget get 4440 over a 4430.  I have both and use them all the time and the 4430 is capable, but the 40 is so much more heavily built and it drives like it.  You need a 1/4 of the foot pressure when split braking, the 3 point is heavier, bigger fuel tank, the 466 is awesome.  I think the overall weight it around 1000-1500# more.  The sound gaurd body is old, but I can still put in lots of long days very comfortably.  All the levers are where they are supposed to be.