Hey guys, just noticed the replies to the thread. The x650 is decent, but they had some major issues with the first version of the electronics that come with it. I ran the stock stuff for about a month and found it just to unreliable. I later upgraded to almost the same set up as janoots, but with only 4 motors instead of 8. The new V2 electronics are just starting to get into the hands of the general public and it sounds like the reviews are favorable, but they still haven't released the GPS yet. That is what will make the difference. The GPS on the original NEVER worked, but they sold tons of them. That sketched me out and I just couldn't see trusting a company that would treat it's customers that way. Even if they have their electronics sorted out now, I personally will never buy another XA product in my life due to the sketchy business practices I have seen them engage in.
Janoots, you should give your build another thought and maybe try it with only 4. To be 100% honest, you don't gain anything by making it an x8 except extra weight. The wookong doesn't handle redundancy, so if you lose one of the 8 props, the counteracting prop on that arm is not going to do you any good. In theory, you are just doubling your chance for something to go wrong (2x the equipment to fail) and not getting the benefits of redundancy. Most all the x650/DJI folks I've seen have done it as an x4, not an x8. The original x8 is possible because all those stock electronics are very small and light weight, not so though with the Avroto's etc. You will get a lot more flight time also with less weight and fewer motors to power.
Learn to fly it as an x4 and save those other motors as either back ups, or for a later octo/hexa build.
Just my 2 cents. Hope that helps!
-Terry