Lumens aren't everything.
My 337 lumen TK15 will out throw my 740 lumen PD32UE because:
Different LED
Different Style reflector
Different tint (cool white Vs Natural white)
The small tight hot spot on the 337 lumen TK15 is almost twice as intense as larger hot spot of the 740 lumen PD32UE (11,592 CD vs 6000 CD)
Figure out what you plan on using the light for? Then pick a light to match your functional needs.
My TK15 would be a horrible light for indoors or around the campsite, but be great for lighting up a person 500 feet away.
Just a couple points of reference.
- My everyday carry light is a Fenix LD10. It has 4 light levels: 3, 13, 45 & 100 lumens using a moderately focused beam. 3 lumens is VERY sufficient for wandering around the house at night. 13 lumens is great for walking the dog, and I live in a rural area. 45 lumens allows me to stand in front of my house and see (dimly) my back fence 300 feet away! with 100 lumens I can easily see my back fence.
- I was in a lava tube a couple weekends ago. While it was fun at times to light up the cavern with 740 lumens, during the majority of the hike I had the light set on 40 or 140 lumens.
All that said, if you want to buy the most powerful AA based flashlight you can find, go for it! It's your decision. Just be aware that the configuration of the light (floody, throwy, tint) may provide results you didn't expect. Whatever you decide on, read the reviews here on CPF before buying!