I don't really have a huge problem with the Civic Center. I was there last night. Little slow getting out, had absolutely zero problem moving around the concourse other than that. Bathrooms aren't very intuitive, but the lines aren't any better there then they were at the Barclay's Center when I was down there in early December.
I dunno maybe it's just a social expectation of mine, but I expect lines, having to navigate through crowd and people being at games, generally - when I go to see live sports. Maybe Fenway Park has just warped my perception.