Received my HL 3 today and so far I have been a little bit surprised and impressed. I haven't yet put it through all of its paces but I would say that it's pretty much as advertised. The biggest surprise so far has been the size of the light. Unlike SureFire with the P2X/P3X Fury, Streamlight used a larger head on the HL 3 compared to what is found on the 2 cell ProTac HL.
The bezel measures about 1.7" at its widest point and I would estimate the reflector to be about 32mm in diameter. When compared to some other 3 cell lights, it's closer in size to the Malkoff Hound Dog (with MD3) than the P3X Fury.
It uses a smooth reflector that produces a really tight, well defined hot spot with a narrower spill beam than a light like the Fury with its smaller and shorter reflector. Beamshots and such will have to wait for the weather to improve (hopefully this weekend).
The advertised ANSI runtime of 1.5 hours is spot on.
Output declines over the first 7.5 minutes of runtime down to what I would estimate as 600-630 lumens. It stays in regulation for almost 45 more minutes before output begins to taper as the batteries are depleted.
For the price, it's looking like this will be a very competitive light.