I don't think there is anything 'wrong' with doing both Akershsus and CRT in the same trip. In fact, I've actually done that!
PRINCESSES: In general, the princesses are pretty similar between the two venues. Ariel, Snow White, Aurora, and Cinderella are among the "standard" princesses at both venues. Jasmine is usually the fifth princesses at CRT and Belle is the fifth princess at Akerhsus. At Akershus, you take the photo package photo with Belle (yellow dress) while at CRT the photo is with Cinderella.
INTERACTION: I found the princesses at both locations to be equally friendly/interactive. I did like the set-up a little better at CRT. The princesses enter to a little fanfare (quick summary of the story; like three sentences) and then follow a set route. So once the first one goes by, you know that when next princesses reaches a certain table, it means you're next. No more having a princess show up and your is full! At Akershus, the princesses don't really have a route so you never know when one will show up. We even had the character handler come up to our table and ask if we'd seen a princess (in our case, Cinderella) yet because she was about to head to the next room.
GAMES: There are no games/activities at CRT. There was a princess parade at Akershus (at least there was at dinner). All of the kids were invited to parade through the dining room with one of the princesses.
FOOD: Neither venue had outstanding food, but honestly, folks go for the experience and the characters. I went for dinner at both and while neither really wowed me, I didn't leave hungry either.
ATMOSPHERE: This is where CRT really shines. Akershus is fine, but there really isn't anything "magical" about the setting. At CRT, you're eating inside Cinderella's castle! Everything about it seems to say "Disney" to me. Plus, kids get a toy wand or sword (adults too if you ask) and a wishing star.
COST: In this way, Akershus wins. It's only one credit (on the
DDP), whereas CRT is 2. If paying cash, I would probably opt to pay the extra money and go to CRT because of the overall experience. If you're on a budget, then Akershus is a good option for princesses.
OVERALL: If you had to only pick one and budget wasn't a consideration, I would go with CRT. I would especially go to CRT if you have children that are into princesses and dining in a "castle." If you have budgetary considerations, then Akershus is less expensive and you see largely the same princesses. If you have the budget, I would do both, especially if your children are into princesses.