The thing that made me interested in these shorts was the built-in compression boxer-brief as opposed to the typical "bikini" brief. I have been extremely pleased with these shorts, and now I have 3 pairs, and prefer them over all other shorts.
The compression boxer brief is not tight or constricting at all, but is snug enough to, er.........hold things in place? During a recent full marathon, I need to make slight "adjustments" only on two occassions. The brief is also very light-weight, so it doesn't get hot. The outer shell is featherweight, and despite the 6.5" inseam, I haven't noticed even the least bit of chafing over any distance or condition.
An added bonus is two "gel holsters" on either hip, which are small -- a Hammer Gel barely fits in thim, but each has a velcro tab to hold your gel in place (although one of mine fell out in the marathon -- operator error?).
I spoke to the Brooks rep at the Expo for the AT&T Austin Marathon, and he said they hadn't had much feedback, as this is a new line, but I told him 5 Stars all the way, as far as I am concerend.