I ran this loop yesterday (September 4, 2010) in the counter-clockwise direction in 4:50:40. Started and finished at the Long Lake trailhead. Have a short trip report here (www.runnersworld.com/antons-mountain-musings/the-buchanan-pawnee-pass-loop) (with photos from a previous run from earlier this summer in the Cascade Creek drainage). Putting some focused effort into it, I think it could definitely be run in the mid- to low-4hr range. However, it's a TOUGH and beautiful circuit!
Forgot to post my splits from yesterday's run, again, starting/finishing at the Long Lake TH.
Mt. Audubon TH: 6:35
Audubon Junction: 27:40 (21:05)
Coney Flats TH: 59:30 (31:50)
Buchanan Pass: 1:46:15 (46:45)
Cascade Creek Junction: 2:39:30 (53:15)
Crater Lake Turn-off: 3:15:?? (35:30)
Pawnee Pass: 4:09:00 (54:00)
Lake Isabelle turn-off: 4:33:45 (24:45)
Long Lake TH: 4:50:40