Warp
Enlightened
I've no knowledge about S2 current draw...but into the 1x123 realm I would opt for:
1)HDS Custom Built Rotary 200Lm USD200 (I own one)
Or in compact 2x123
Quark "X" 2x123 (handles very well 1x17670RCR, has thermal protection)
Not rotary
Better bang for value?
EagleTac T20C2 MkII XM-L which has many output levels, thermal protection, upgradeable led/reflector module and many many goods into standard package. You can find it for less than 100USD. It is rated for 720Lm (480 Ansi FL-1 lumens) and mine eats AW's 2900 flat top 18650. Not bulky at all.
Bulky is relative. The T20C2 isn't a pocket light and compared to a JETBeam RRT-0 the T20C2 is, well, massive. It's a cargo-pocket light, perhaps.