Maximum Brightness measured was Reference mode, zoom at wide angle, color space set to DCI. That worked out to 1925 lumens, just slightly less than the 2000 lumens claimed. Reference (along with Game mode) is the brightest overall. It also starts out with great color balance, so was Mike's basis for calibrating the projector. The various modes use different color spaces, Eco (low) lamp mode or high), and other settings changes to offer a range of brightness at mid-zoom from 454 lumens up to Reference's 1537.
The short version though is that Reference is the brightest, and even calibrating it barely affects that claim. Use other modes where applicable. For example, I suspect that Cinema Film 2 with it's warmer color temp is set up to do a good job on black and white films which in the old days used a color temp in the 5500K range.
1500+ lumens qualifies the Sony projector as a "light canon." More to the point, with a typical 1.1 to 1.3 gain screen, you can tackle screen sizes up to, or even beyond 150" diagonal! If you want 3D that's not on the dim side, you'll probably want to go no larger than 130" diagonal, unless you have a higher gain screen. Of course you could use lens memory to carve out a screen image size that you like for 3D brightness, that's smaller than your full screen.
Of note I like Bright Cinema as well. It doesn't measure as bright, but the default selection of its gamma, color space, etc, provide what appears to be a more saturated image that can cut through more ambient light without being washed out. I often use it for sports viewing when I have a fair amount of ambient light allowed in. If I'm watching a game at night, though, no need to switch out of Reference.