Which direction
RickM, you didn't ask for my opinion, but I'm giving it to you anyway.
Like Jamie, I prefer doing the Pemi Loop in the counter-clockwise direction for a few reasons:
-- You get the 4.9 miles of the Wilderness Trail done first, usually in the early hours of the morning when you're not fully awake yet anyway.
-- You get to DESCEND the steep 8/10 mile from South Twin to Galehead Hut (admittedly, this may be a negative point for folks w/finnicky knees).
-- The north side of Lafayette is spectacular, one of the gems of the White Mtns., IMO! It's spectacular doing down, too, but I just enjoy going up it more.
-- Bondcliff Ridge is VERY nice, but Franconia Ridge is above treeline much longer and nice to look forward to at the end of the day. (Caveat: if the weather is iffy, I recommend going clockwise so as to get most of the above-treeline stuff done first. This is the main reason Frodo, Sir Edmund, and I did the Jan. 2005 Winter Pemi Loop in the clockwise direction... keeping in mind, of course, that the winds are predominantly from the NW and thus usually in your face.)
-- The Osseo Trail is less rocky than the Bondcliff and, therefore, easier--and more fun--to run down.
-- That's about all I can think of right now!