Nor. Epic is a large ship but except for the pool deck (deck 15) and buffet, you don't know it's got so many people. We were a family of 4 (two teens) in adjoining balcony staterooms. Deck 15 was packed as were the small pools and water play areas. Found a quiet spot all the way forward on Deck 16. A Med cruise, there were lots of non-US citizens. Passenger manners were few and far between - seemed to be a lot of pushing and shoving. One woman pushed a stroller into an elevator with about 10 people without hesitation.
CHECKIN: Was a little crazy as we waited in line for 45 minutes before getting to the counter. I have no idea what was taking place watching some of the animated conversations at the counter. We checked in, the agent checked out our passports, took our pictures, and gave us IDs. Maybe people were trying to upgrade? One family was at the counter for almost 30 minutes.
FOOD: Free style is great. If you want to avoid the crowds in the buffet (I recommend avoiding) hit the Manhattan Room. Pants and collars required, but many are not inclined so the clientel is nicer, better behaved. Seems like more senior wait staff is here, too. Go before 7:30 as the post-show crowd forms a queue. They had couples doing cabaret each night from 7 to about 7:40 as well. We always dined before 7 and never waited. Taste restaurant is also sit down, but no dress requirements so a little more rowdier. You can get an alcohol plan for $49 per day. A beer/wine drinker, that was about 9 drinks a day to break even. I don't recommend it.
13157/13159 adjoining: Under the kids rec center but not an issue. Never heard anything. Probably a plus, but we were midway between fore and aft stairs/elevators, probably limiting the walking traffic.