I don't know of any legit E90's cheaper than $900 right now, so that makes the Wing attractive if you're on a budget. If the camera and GPS (weak though the GPS currently is in the US) make a big difference to you, then the E90 is worth it. But if those aren' that important to you, when money is important, the Wing is a good choice.
-------------------- Lisa Gade Editor in Chief, MobileTechReview