The 365"X" version is the same machine as the 350"A" but I suspect the
A is being phased out. I got my A for about $1200 at a wood show. X
may get you some extra goodies like a mobile base if the promotion is
still on, but otherwise the only difference is a 5 year warranty and
some snazzy decals, which I don't think is worth an additional $300+.
My 2 cents is that the 380 is lighter duty and of the older design as
someone noted, and the A is in my judgment well worth the extra $300
over the cost of the 380. If the warranty is important to you, get the
X, but with either the X or A you will have no regrets and its likely
the last jointer you'll ever need.