I've been trying to get a Heli to play nice with APM2 and it has been a rocky road.  It finally kind of working fine, but it's still a pain in the behind in most cases.  I've seen so many video about people flying  the multicopter and they are so calm and stable so I want to get one to try it out.  Eventually, I would like to get it to carry at least a Gopro and a video TX.  That combo alone would weight about 400g.  I've seen quite a few people mentioned X525.  What are your recommendations?