I've got the older GX470 and it's my understanding it's pretty much an older Prado (LC) rebadged as a Lexus, obviously panels and interior are different. I know Koz has the new GX460 and it's the rebadged LC for the US with a LOT of upgrades from the new Prado (LC).
I chose my GX470 over the '11 4Runner TE because the 4R left me underwhelmed BADLY. Great offroad truck I suppose, but it needs more balance for those of us that don't offroad every day. (I've got an offroad toy so that helped my choice)
I was at the dealer having the clunk TSB taken care of and looked in the GX460 and DAMN! It's flipping nice inside.
I'll say this, the GX460 looks SOOO much better in person than it does in pictures. It's pricey but I really doubt my next vehicle upgrade will be anything but the GX460.