I agree with the PPs that it really depends on what your focus is.
Economic Value: Akershus is only one credit.
Princesses: Generally the same princesses are at both venues, except that Belle is no longer at CRT. Most reports seem to indicate that Jasmine is her replacement (that's who I saw in October). The photo op at CRT is with Cinderella and the photo op at Akershus is Belle (yellow dress). It really comes down to whether you want to see Belle (then go to Akershsus) or not. At CRT, I saw Cinderella, Ariel, Snow White, Jasmine, and Aurora. At Akershus, I saw Belle, Cinderella, Ariel, Snow White, and Aurora. Character interactions were fairly similar at both places, but I liked the fact you could tell where the character was going to go next (i.e., they followed a set pattern) at CRT. At Akershus each princess followed her own pattern, so I couldn't really gauge when they'd arrive at my table.
Food: It's kind of a toss up. The food at CRT is okay, but by no means excellent. The cold board at Akershus was pretty good, the entrees and desserts were okay. If your focus is food, then I'd say it was a toss up.
Toys: CRT has wands and swords for their guests. They'll give them to the adults as well, not just the children. Each guest also gets a wishing star. At least my all-adults family did last October. Akershus doesn't have any toys.
Service: It can be hit or miss like any other restaurant. Both move a pretty quick pace, but because CRT is all plated, I think they have a little better handle on how fast to bring out the entrees. At Akershus my family had just returned from the cold board when our entrees arrived.
Atmosphere: Nothing really beats eating at the castle. I tend to say, if you've never eaten in CRT, you should try it at least once for the experience.
Overall: If cost isn't a factor, then I'd go to CRT. If cost is a big factor, then I'd consider going to Akershus instead.