I own the Surefire G2, had a 6P, and both of those had identical light outputs for me, so it would be whether you want a Plastic or Metal casing.
I think that the 6P was very close to the Streamlight TL2 in terms of brightness, but I preferred the TL2, in terms of the recessed tail switch and ability to focus the beam better than the 6P. I felt that the 6P's construction held up better than the TL2 though.
I've also got the Twin Task light, and I agree with the other opinions here regarding its use. Yes the switch is nice, but the Surefire can also be setup to be a one-handed turn on as well. My grip with the switch was that if you soley wanted to use only the LEDs or only the Xenon bulb, you would have to press 1x to turn on the Xenon, 1x to turn it off, 1x to turn on the LED, 1x to turn it off, 1x to turn on the Xenon again. So from off, you'd have to click it 3x to turn it back on... so I found that'd I'd set it up for one way, then need the other, or unnecessarily have to click more than I'd like.
But the Twin Task is my Goto light in the car/Truck... you can't beat a dual stage light that runs off Lithiums. I also keep a few Mini Maglite with Nite Ize LED's in them as well in the car.
On another note, it seems that you are looking at lights in the price range of $40-60, from about 60-80 Lumens, so I figured I'd shoot you this site to check out. The lights are all custom made, and you might not believe the claims, but consider, these are custom made, and have lots of reviews on
www.flashlightreviews.com and at candlepowerforums.com. I'm about to get a Blaster JR myself.
I really recommend you check out Elektrolumens.
http://elektrolumens.com/
For the price, a Blaster JR or the Blaster 1R are very nice lights.
The Blaster JR, is about 70 Lumens (I'm pretty sure the consensus is in that area), and runs about 8 hours off 3 AA batteries in a Mock D cell.
The Xm-3 runs about 2 hours at 70 Lumens of 2 AA batteries. Its a 3 watt LED.
Then he's got some of the really really bright lights that run $150 and up.