Most impressive were the array of extra parts included in the kit--extra screws of all types in case you drop and lose one (or more...) and two each of the different allen wrenches. Battery included, too. About the only thing I can find "wrong" with it was that the receiving threads on the unit for the battery cover seem to be polymer/plastic. You've got to have that cover plate lined up just right, or you risk cross-threading it. At least the mounting screw for the rail has a captive brass nut of sorts on the left-hand side.
The different modes are easily selectable, and right now I have the unit set to mode 4, which is the pulsing laser only (no light.) This extends the battery life from 4 to 7 hrs!
The tac light is good, and quite bright. If you select a laser+light mode, the green laser is easily visible, and is not a problem to pick up. The strobe mode is nice, too, and is a nice touch to the mode options.
Viridian lists a whole bunch of compatible holsters on their site, and there are quite a few choices available, depending on the purpose or preference.
I must say that the price was a little high, but I do like the unit.
Ammo by Dillon and Hornady