The new A330 flies the MAN-PHL route with Sony P@ssport Entertainment system at every seat...tons of movie and tv choices that you can start/stop/reply/etc. as you wish. Two food choices in coach, but they frequently run out of one of them by the back of the cabin (order a special meal if you're picky). Lunch after takeoff, light snack before landing. Crews run the range from friendly to surly, but I'd bet you have a good chance of getting a good group.
Customs/immigration at PHL isn't too bad, however all the intl flights arrive at the same time so there is occasionally a queue. You'll have to claim your baggage and walk out of customs to a re-check desk for the domestic flight to BOS. The re-check experience is usually very chaotic with lots of people heading in all directions and agents barking all sorts of information; provided your bags are tagged all the way thru at MAN you should have a pretty easy passage (throw them on the belt and head to your connecting gate). You'll have to change from terminal A to either terminal B or C for the BOS flight.
PHL-BOS operate every hour. Don't expect much in terms of service; this is a businesspersons' flight and there will be a beverage service at most; sometimes they have only water & Coke to choose from, while other times they don't come thru the cabin at all.
US has a pretty good intl product. Domestic on such a short hop is nothing, especially conpared to a European short-haul. Enjoy your trip.