I've never heard of that service, so I would probably stick with UW just to be safe. But I will say that of the 10 sample questions, I thought 3 of them were lifted directly off of my step 1. Weird. For $59 I guess it doesn't hurt too much to try it.
posted on this a while back - so not worth it especially if you don't have much time there are other, far better adjuvants to UW such as Qbook, BSS, Robbins review.