I would say the only negative, and not much of one if I want to max out on sleep, is Odyssey IFE on the A343 out of IAD versus V-Port on the A346 out of BOS. With either option, I would have to change terminals: A to E in BOS (CO to VS) or C/D to B in IAD (UA to VS). Don't know much about any differences in the VS Clubhouses in each, so I guess that ain't an issue.