I just paid for the 2 stage...
And I wasn't too sure I really wanted one until I actually tried one (one someone else's AR) and it delivers the perception of a lighter trigger pull - the true break is, say, 4.5 lbs., but because the initial stage is lighter and the increment is small to get to 4.5, it just feels lighter. It's not particularly important for CQB or kickin' doors in (though it probably doesn't hurt and might help when reachin' out to touch someone...), but for long range CMP high power matches, it almost mandatory. That 4.5 single-stage feels like 14.5 lbs by the 20th off hand shot!
" It's really simple, just focus on the front sight...yeah right!"