This is a great little tac light. It's very bright for its size, but has its limits. You're not going to use this light for long distances or large areas. I use it mostly for a home/hotel room defense light. I'm an NRA instructor and use this light for training self-defense classes.
The high setting is very bright once your eyes are night-adjusted. THe low setting is bright enough at night to navigate around the house. The strobe feature has limited uses (alerting, disorienting someone?), but is a nice inclusion. The ProTac 1AA is weather-proof. I tested this by using the light under a stream of water at all angles. No problems. The end cap switch is easy to use and intuitive; partial depression quickly to change modes, then a full depression to stay in the selected function. The rim of the light has notches that let light escape. This is good in two ways, it lets you know if the light is on if you happen to set it down on the lens-end, as well as helping control the amount of light by placing a finger over the lens.
This is just the flashlight I was waiting for from Streamlight. If you need something brighter or bigger, they have the 2AA model as well as two lithium cell models.
Optics Planet was great as well, shipped it as soon as they became available (I pre-ordered) with emails to keep me up-to-date on status. The only thing that wasn't clear on the website was the fact that it was a pre-order (I knew this going in though).