I've come around to this transfer, but more so as a 8 replacement for Xhaka than to replace Partey as a 6.
Rice has tremendous stamina and pace, and with that we'll be able to both press and recover better than we can with Xhaka. Fair credit to Xhaka though - he certainly helps out defensively but Rice will bring us up a level, and with a game type more in tune with how to play in Europe.
Not sure I like him as our sole DM though. Too much of his game is based on his ability to push the ball past a man on the run, and I think it'll be hard to curb that skill/instinct which we need from our 6.