Well, everyone seems to be forgetting US Airways. Here is the BOS breakdown"
Most flights: American (140, 83 Eagle 57 Mainline), then US, then DL...(UA is a distant fourth with 45, the rest have 100+)
Most destinations: American/US Airways (I believe both have 31, but U has been doing a lot of tinkering at BOS)
Most passengers carried: Delta (DL has over 25% of the market)
AA does indeed serve both LHR and CDG from BOS. I don't think ZRH is on the radar, as we have Swiss (AA codeshares on BOS-ZRH) and a new MUC A340 which is close to ZRH. FRA is underserved (1 A340 in the winter, 2 in the summer), so either AA or DL might come in on that route.
As for BOS, the AA terminal is nice. It is always packed, but it is very clean. It was just renovated a few years ago. As for viewing aircraft operations and using binoculars/cameras/etc. THAT IS A NO-NO AT BOS!!! What happens varies, but they might make you destroy your film (erase digipics), put away your binoculars, and take your notebook for tailnumbers away from you. If you not there with a "reason" they will kick you out and give you a trespass file, which means you can only go to BOS if you have (as the state trooper said to me) a "reason" for being there, like dropping off pax or flying. Unfortunately, BOS has gone downhill from being a spotter-friendly airport to being an anti-spotting machine. For more info on this, visit http://groups.yahoo.com/group/bostonloganintlairport
. We are launching a campaign (Led by me) against the anti-spotting behaviour there, and we could use the help.