"Only 35-40 degrees"
I love it. I was talking to someone else in GoS this past Saturday and mentioned "how mellow" the gullies were at the bottom (I didn't bother skiing the run out of Main Gully #1 before booting back up for another run). And he replied that "I have an interesting sense of pitch!" or something along those lines. To which I replied back having skied over the lip in Tuckerman two weeks ago, everything seems pretty mellow in comparison.
I was up in the Gulf of Slides as well on Saturday. I will piggy back on your TR with my experiences. We went different ways so probably never bumped into each other though I got started only 15 minutes later than you guys. After skiing the Main Gully, I kept going one gully to the north each run whereas you guys went south towards the snow fields. Sensational skiing if a tad on the warm side. I have a differing opinion on the Gulf of Slide trail as I skinned up all but 20 minutes of hiking with only two short portages and skied down the same exact amount that I skinned with a short 15 minute or so down hike in the middle. It was mostly survival skiing, but I had my skis on my pack far less than any one skiing down the Sherburne for sure. Here were my runs:
Gully #1 (and snowfields): 
Gully #2: 
Gully #3 (four image panoramic): 
Photo Gallery and
Trip Report