Adrian,
just to bring a bit of balance into these posts - there are other regs than the grossly overrated Apex offerings
I use Cyklons, a dead simple design that actually improves with depth - they can be a bit of an acquired taste in shallow water if set a little fine but your air consumption should improve as you are more aware of each breath.
For me the big advantage is that they are not shoulder dependent. I use one over each side.
Bullet proof as well. Worth a look/try and nothing to twiddle. You can stick your finger into the second stage to prod the venturi though (without gloves).
Cheers