Centring looks about right to me. With the large tail, it needs to be slightly lower than usual but it looks balanced enough to me. The contrast is quite strong so it may get a contrast or dark rejection here. Sharpening and colour balance look fine on my screen.
Darren
Equipment: 2x Canon EOS 50D; Sigma 10-20 EX DC HSM, 50-500 EX APO DG, Canon 24-105 f/4 L, Speedlite 430EX