Bit of history here....bought a '16 X590 in April of 2016. Put 48 hrs on it until May 24 of 2017 when I traded it on a 2017 X738. Both are 54" decks. Both are absolutely amazing mowing machines. The X590 is a quite a bit smaller machine so the nimbleness is definitely appreciated in tighter quarters. The X738 is quite a bit larger, so going in tighter spaces is a bit harder. I think I like the 54" HC deck better on the X738 than the Accel 54" deck. I think the HC deck is quieter as well. The PTO engagement is definitely a lot smoother on the X738 as well which can be expected for PTO vs belt drive. The 4WD on the X738 is simply amazing, no more spinning tires when backing up hills while mowing. The X590 is a superb machine, but the X738 is better in every way so far that I have used it. Can't wait to push some snow with it this winter! The X738 rides so much better as well on rough grass. Any questions? Ask away...I will try to answer them. The front fenders are an absolute must add-on as well. Keeps the deck so much cleaner, especially in really dry grass.