We boarded in Rome although it appears that Barcelona is the favored starting point. This worked out extremely well since the embarkation in Civitavachia was the easiest we've ever experienced in a dozen or more cruises. Also you can so some justice to Barcelona in a day, doing Rome in a day, when it's 40 miles away to boot, is foolish.
Epic is huge and I understand the mixed reactions people have to that. The thing that struck several of us was that the absence of the big central atrium that you see on RCL and Carnival made it seem more like a floating hotel than a cruise ship. Although admittedly it made navigating around the ship simpler. Clearly they traded functionality for WOW! This was our first experience with Free Style cruising and we were generally pleased. Food at all venues was good, certainly much better than we had recently on Carnival. I'm not a big fan of paying extra for food at the specialty restaurants although we did it twice. Food was good but paying $15 and $25 extra, respectively, for Chinese food and Tepanyaki was excessive. Similar feeling about the food charge in Cirque dreams. (More on that later.) Contrary to the views of some other reviewers, we thought to the food at the late night venue was pretty good. Liked Manhattan dining room. Taste is a little noisy with the casino above it. (Re Casino: First ship I've been on with live, as opposed to electronic, Texas Hold'em)
The cabin arrangement is certainly unique. I enjoyed the larger shower but it takes a while getting used to the location. The Opaque glass is different. Didn't bother us but I could see how it would perturb some.