One of my colleagues flew them BOS-KEF-ARN in J last year. I told him he was crazy since the price was the same as BA or KLM, but it fit his schedule better.

The BOS-KEF flight was a 757, and he called it "spartan" but he doesn't fly enough to upgrade to F domestically. After asking him a few questions, it sounds like it would be sort of like flying an America West BOS-PHX.