What configuration is better, x8 or 8? What are the positive things for prefer x8 over 8 and viceversa?
This has been discussed at length here on the forum. Use the search function and there's a wealth of information. Better to do that than ask to start Yet Another Flat vs. Coax Thread.
Raul: As Steve says, there's quite a lot written about this. Unfortunately, you cannot just search for "X8" as the string is too short. Try searching for: convert x8 Andy.
You can search for "COAX" and you'll get quite a few threads on the topic. In a nutshell, Dave King is a huge and successful proponent of flat copters, and I and a few others went the way of the coax (X8). I've since sold my copter and moved to the ALTA, so I'm out of that game.