We just returned from the kind of trip you are looking forward to, and visited both CAs. The one in Boston is indeed worth seeking out: spacious, comfortable, and quiet. The one in NYP is considerably less so - while it surely beats hanging around the station itself, and is useful for storing luggage, it is low-ceilinged, often crowded, uncomfortably warm, and has a centrally located boob tube that is always on - loud enough to disrupt reading or thinking, but not loud enough to drown out the unruly children or loud conversations at the reception desk. And while the desk does announce the boarding time of trains, this does not spare you becoming part of the mob scene at the top of each escalator. On the plus side are the bathrooms, the free soft drinks (though the pastries, when available, taste of cardboard), and I always make use of the shoe-shine machine, common to European hotels. But overall, weather permitting, we prefer to spend most of our layover time wandering the (not particularly attractive) streets outside rather than in this particular CA. (Just my opinion!)