I don't think there's anything wrong with saying he's potentially as good as/better than Gerrard. The key word is potential. He doesn't look the same type of player to me, but he has all the attributes to be an exceptional midfield player, just like Gerrard did, and was.
I'm sure we'd all love it if at the end of his time here he can be even mentioned in the same breath as Gerrard, because it'll mean he's had a long and successful time here.