I smiled when the OP said, "who on earth connects" on the SFO-BOS route...that's one of the longest domestic flights in the "lower 48"...it's REALLY easy to connect (even on UA via IAH, CLE, IAD, ORD, DEN, and/or LAX)...and I personally would rather pick up the extra miles and stretch my legs a big rather than have one long 5-6 flight, especially if I were in E- like I assume the OP was. For me, I actually have been hesitant to book US transcons since they got rid of all in-flight entertainment years ago...I've been on a lot of UA flights with DirectTV and I must admit, I'm hooked (even if I have to pay the $7.99 it costs in Y). I don't have all the latest electronics to drag on board the plane so sitting for 5 hours looking at the seat in front of me doesn't sound like much fun. And speaking of connecting, when upgraded to F on cross country flights (even some mid-cons), it is possible on UA to get two meals (for example, breakfast on SFO-DEN and then lunch on DEN-BOS)...is that even possible with US given their lack of hubs in the middle of the country and their super strict rule about not serving meals in F unless it's over 3 hours (or is it 3.5??)....and then there are the RPUs....