I linked you both the gen and the rep. Take a look. If you cant see any tells on your own then knowing the them wont be of any beneift to you. But there are plenty of threads on the PO specifically, so check those for the issues with the current version of rep POs.
Read the thread Mr.Pap linked to and then buy the orange 42mm (which you like) I think you'll be pleasantly surprised. What could go wrong? If you are trying to decide between black or orange bezel colour ?? then these might help also:
You have to understand that these same questions have been asked a thousand times yoma, and answered by the guys here time and again.... they can all be found on a search, the members cannot choose which one you prefer. If you have any more specific questions I'm sure they'll be answered.
Yoma, there are no V4's available from the dealers now...older model, the only place to get a V4 is on the 2nd hand rep market. All available new now are V5.