Carla, RCCL is definitely more "subtle" than Carnival. (Personally, I'm not a fan of Joe Farcus' design either - he's the one that does all the Carnival interiors.) Family cabins are a neat idea, but they are probably more expensive than a couple of adjoining or neighboring "regular" cabins.
Using a TA will definitely save you time and effort working with all these variables. Find one that you trust - preferably that you can deal with on a personal basis, either face to face or over the phone. Not all travel agents are out to push the numbers with a cruise line! The good ones are concerned with helping their clients have a good vacation that meets their wants & needs.
If the "best deal" to you is more than just lowest price, but is more like good price plus good service, then go with a TA.