As others have said i'd go for whichever city you prefer.

the lounge in boston i found pretty rubbish to be honest - dark dingy and the TV Was on INCREDIBLY loud. The restaurant (where they offer preflight dining on the sleeper service) was actually bigger than the lounge i recall. but there were DEF no windows as it seems to be in the basement or certainly on the lower floors to the departure gates.

On that basis JFK concorde room wins hands down.

but as others have also suggested you could do an open jaw and fly into boston and out of JFK.

And personally for F i prefer the nose of the 747 over a 777, has a bit more privacy certainly in 1a/k and 2a/k.