Same as others have said I still use V4 because I have a load of stuff for the figure and it works well for everything I need. I'm not interested in buying/converting stuff for a newer figure. (I still use M3, A3 and H3 all the time too - never liked M4 much). I've just about stopped buying any new items for the last couple of years because I can't be bothered to wade through sites looking for stuff for V4 and I have so much stuff that I can re-texture and kit bash and convert - I'm never likely to run out. I would only move on from V4 if there was a new figure that actually offered something completely different that I really wanted and it hasn't happened yet.