I don't know anything about either place, but I do get interns from time to time. Besides learning, an internship is also a good time to network. If one has you meeting and working with more people, this may help you further down the road.

According to you the Tetons offers a stipend, according to Aimless the Tetons might offer more opportunity to network. Unless there are other considerations, the Tetons sound like a better option. That doesn't make the other a bad option, just one a little bit better.