I think the Fenix TK40 deserves a mention here. Although it is rated at 630-730 lumens(disputed due to rumors of a brighter 2nd generation) Fenix has recently been much more conservative with their output numbers. Also the Eagletac has 900 lumens at the emitter meaning that you can expect somewhere around 750 lumens usable lumens out the front. The TK40 runs on AA's which may be a positive or negative depending on your personal preference. Just something to think about.
+1
I actually had been seriously considering the TK40 myself until I began reading this thread. One of the things the TK40 offers is a smooth artifact free beam. I am not sure about the beam with the EagleTacs.
The beam shots on flashlightconnection.com, don't tell the whole story.
I am anxiously awaiting reviews that will compare these two lights since they are priced so much the same and claim to have similar outputs (can you really see a difference between 730 lumens and 900?) Whether their beam quality, throw, runtimes, and spills are comparable remains to be seen. While for me that is more important than the interface, I do like the interface on the EagleTac a bit more that the TK40's. With a larger flashlight, I think having level controls near the head of the light is more convenient than having everything controlled from a tailswitch, as on the TK40
Besides this, what has made me hesitate about the TK40 is the battery supply. I personally don't think a flashlight that uses 8 cells of any type is a very advantageous thing, even if they are readily available as primaries. Since most chargers only charge 4 cells at a time, the use of 8 cells, even AA cells, seems too time consuming to me. Using primaries is out of the question both in terms of expense and poorer runtimes compared to NIMH cells.