It's a bit early to say with these Sandforce based drives what effect losing TRIM will have. They are supposed to have very good GC to keep the drives clean. But i don't think anyone has had the Vertex LE long enough to be sure of this.
Plus, the level of performance that the Vertex LE is pumping out, i doubt you will notice a real difference in speed with RAID0. Also remember, if you want to copy files around, you'll need a very fast RAID0 array to copy the files too, if you want to take advantage of the speed of the Vertex LE array.