The folks over on Candlepower Forums, including the LEO guys, pretty much all sing the praises of the TK10/11. The P3D is great, too, but it's different kind of light and not really a "tactical" light. People went crazy doing all kinds of torture tests with the TK10 on CPF and it took a lickin' and just kept on tickin'.

Just to throw out another option--Wolf-Eyes. The 2-cell Sniper model is built like a tank and I really like my Wolf-Eyes. I have the Sniper and the 3-cell Raider models, and have used them as incandescent and LED lights by swapping out the lamp assemblies. These work equally well with CR123 batteries, or rechargeable lithium-ion cells.