In my experience, as of now, there are 4 versions of this watch. You can tell them apart by such:
V1: 60-click bezel, slightly thicker than V2, no forth marker after the 10 on the top sub dial, incorrect font on the date wheel, nice and deep bezel markers.
V2: 120-click bezel, slightly thinner case, four markers between 10 and 15 on the top sub dial, incorrect font on the dw, correct but not as deep bezel markers and tab numbers. The locations of the bezel makers are close to gen.
V3: Same look and feel as V2 except it has correct font on the dw. However, please do note that I said look and feel. Most dealers sell these as V2 + corrected dw.
V4: Most dealers sell this as V3. I'm not sure how many clicks on the bezel. Although the bezel markers are nice and deep which more gen like, all the markers are more closer to the outer edge of the bezel than gen.
From what I read somewhere, V1 and V4 are made by the same factory whereas V2 and V3 are made by a different factory.
My experience on the bezel tells me V2 BCE is probably the best of the bunch, but you will have to fix the font on the dw. Breitling dw is hard to find. The V3 is good too, if you are never going to try to install gen bezel, you should go with a V3.
V4 are nice in a lot of ways. I especially like the deep bezel markers. To a lot of people, they won't know the difference.