Hi,
@Shobos,
The ESC version 4 and 5 are interchangeable. I remembered you were looking at this at the end of December. I saw your post, still looking, so I looked at some of mine. The third Q500 I looked at has a V4 on the left front, and a V5 on the right front. This bird flies the same as any other. Never noticed anything odd about it's flight at all. Hope this helps.