The $250 difference probably won't allow you to buy down 2+ pounds. It's a tough call on the Ace since nobody can really tell you how it's going to ride. The reviews on the Riddik seem to be pretty good, so one could assume that the Ace will be similar.

A good set of wheels, fork & tires could run you $1k. Me, I'd wait a little while until the reviews on the Ace start coming in. Then you can make a more informed decision.