Pick your mode, the LS10000 is bright. As you can see in this table, here are the lumen measurements Mike came up with, for each mode, along with the color temp of white for that mode.
For these measurements the zoom lens is at mid-point. That means there are a few more lumens "under the hood", if you can mount your projector at or near its closest point to the screen what we call full wide angle.
Although I definitely consider the LS10000 to be a home Theater projector - best when placed in a first class room, with great lighting control, and lots of dark surfaces, it does have the muscle to do media rooms that aren't near as dark, and even some family rooms and living rooms. That said, In rooms without great lighting control, you lose the benefits of the great black level performance.
So, while the LS10000 might be versatile enough to journey into more "common" rooms, it won't be at its best. Still, it will beat almost anything else you can put in those rooms, short of some high power home entertainment projectors that are no match in terms of picture.
BTW in the best modes, such as THX, Epson calls full power Extra Bright. Mike reports that unlike lamps, adjusting the brightness of the light source has virtually no effect on the color output.
Normal - the medium mode, brings about a 23% drop in brightness, while Eco works out to almost a 46% drop. Eco mode is the mode where Epson rates the laser light source at 30,000 hours. Let's guess 20,000 hours for the brighter modes.