I'm coming into the conversation a little late, but I'll say that I've done trips with both the groups mentioned here.
I am trained as a Group Leader with AHS, although I've not had the chance to do that. I did a trip with them into the Cottonwood area for a week, up the South fork trail, and worked the trail from Long Lake to NAP, and from South Fork Lake #1 to Cirque Lake. My experience was excellent. They had very experienced and skilled leaders(one was the Wilderness Manager for Whitney--you want to affect policy, this is the guy to spend a week with!), the food was amazing (packer supported trip), the participants were fun. I believe that I was the only person from California, and a number of people were veterans of this group. They clearly enjoyed this as a vacation, and liked that there was a organizing entity that took care of the details, that they could depend upon. I think that is the key, that they were from far away, and dependent upon others to make their vacation work.
I am also a Crew Leader, and trail skills instructor for the High Sierra Volunteer Trail Crew. I've done perhaps 30 trips with them, and am often the crew leader. The makeup of the people is quite different. It is primarily local people. They are doing a job on the Inyo in May, to replace the bridge on the PCT 2 miles north of Kennedy Meadows. I'll be doing several trips with them this year, including week-long backpacking trips in the deep Sierra. I've seen a lot of terrain that I would never have, if not for these trips.
The second group's trips are free, however, they spend enormous amounts of time fundraising, and it is a big effort to support their schedule. I'm sure it is over $100k, and it is limited to really 1 or 2 forests.
This stuff is astonishingly expensive to put together, and I guess it becomes a balance between having paid employees (both do), fundraising, organizing. I'm sure these represent two of several models.
While somewhat differently organized, I'll say that I have enjoyed working with both groups a lot, and think very highly of the work they do.
