Tester's T3

There are quite a lot of different options out there. Any idea what the aero pros/cons of each are?

You're getting into the deep nitty gritty if you try to find the fastest hand position - it depends on what's following, so there is no generalised right answer, only the right answer for your particular body, taking account of what the air does after your forearms have had at it, and what your legs feel about the matter, since eventually you have to balance power against drag. Not only will the 'perfect' solution change as you adapt, but it will be different at different speeds - 10W of power loss that balances 10W of aero gain at 20mph suddenly becomes closer to 30W of aero gain once you're doing 30mph, so as you get faster the balance of the trade swings towards sacrificing more power for each hundredth of a square metre of CdA you can gain.