Both are roughly the same. When you get this high up the SSD ladder, there is never going to be a clear winner. The Vertex will win in one benchmark, then another drive will win in the next, etc. Then throw in the complication that both drives will have firmware updates that will improve performance. So its not as easy as saying one is better, but either will be fine. I would (and have) personally go with the Vertex 4.
Heres a review of the Vertex 4 with the newest firmware, 1.5. Just keep in mind to compare the scores of similar capacity SSD's. Due to the technology behind it all, higher capacity drives perform better than lower capacity ones.http://www.anandtech.com/show/6074/ocz-vertex-4-review-128gb/6