I have this Bixler 3, it seems very tail heavy to start with. The recommended 3s 2200Mah doesn't balance the plane out. I've been flying a 4s 2700 and it gets balances with the FPV canopy, using the wing spar as the CG. It also balances with 3S2P 2200 but I haven't tried it yet.
I'm a beginner pilot and this plane is very easy to repair, can't fault it. Its really taking a beating from me and when I finally stop making mistakes its only 13 dollars (plus customs) for a new body.