I sailed on the Epic on their Eastern Carib cruise over Easter Week in '11. The crusisers were myself and my wife, (both early 30s) and her mother (you can do the math

), and we all had a great time. There were plenty of things to do on board, but we weren't sailing with little ones. We're more puppy-people than kid-people. DW & I can't wait to go back...as a matter of fact, we were thinking of jumping ship (poor choice of words, possibly) from
DCL to NCL for an upcoming cruise with my MIL who is going back on the Epic...we just couldn't make the dates work due to stuff we have going on on land the week she'll be at sea.
We loved the Ice Bar, Howl at the Moon, Second City shows (both family and 'adult'), and other fun stuff to do on board. I know there were some Spongebob things over the week, but we didn't pay much attention to them. The pools were very nice, and the waterslides were great by cruise ship standards.
I haven't listened to the podcast about it, but I'm going to guess the main complaint was the freestyle dining. We had mixed reviews on it...liked the freedom to pick our dining times, but the MDR food wasn't anything too speacial, but we did like the sports bar, and the fact that it was open 24 hours so if you wanted to drop in for a snack after swimming or what have you, it was ready and you didn't have to wait for room service.
If you want to try something new, I'd suggest doing it. I think DCL's in a bit of a rut as far as where they are going, so after we take the cruises we have booked (a 3-night in 2 weeks, then PCC 4.0 in dec), we might start exploring other lines more (we've done the Epic cruise, and the Carnival Legend out of Tampa, where we live...that was a fun ship, too).