Balancing Your Rig
It makes common sense to make sure your rig is neutrally buoyant. I'm surprised how many aluminum housing DSLR shooters don't balance their rigs. The most obvious reasons:
1) Ease of handling/shooting
2) Less need to use air in your b.c. or drysuit to compensate for your non-buoyant rig
3) Less problems in an emergency situation
I actually find that buoyancy is more an issue with macro than wide angle. Your framing and focus is more crucial with macro. Thus holding your camera steady is more crucial. In California where I dive, is usually need to steady myself on the reef with my free hand because of currents and surge. Holding a Subal housing and 105 mm macro lens will tire your forearm fast, if it isn't balanced.
Wide angle is less of a problem.
Aluminum buoyancy arms and floats add to resistance while swimming and will add weight and/or bulk to your travel gear when traveling overseas.
I recently changed to micro 4/3 and an O-M5 in a Nauticam housing. I'm trying to work out the buoyancy bugs with this system. Much less of a task then with a 1.5 crop factor Nikon DX.
UW photography, like life, is all a balance. Balancing floats/arms can be done as much as you want.