We have not done the lunch at Akershus, but we have done dinner at both it and CRT and in my family's universal opinion, Akershus was a far superior experience. The food was far better at Akershuus and the options were more creative, the character experience was less rushed and the princesses were very sweet with both DD5 and DS2, and the service was comparable, if not slightly better at Akershus. Please note that, in our opinion, CRT was not bad, it is just that Akershus was a far more enjoyable experience for our family.
For our upcoming trip, we offered DD5 a choice of dining at one or both of them again, so she did not have to pick, and she chose to go back to Akershus and chose not to go back to CRT. Considering that she is as princess-crazed as they come, that's quite an endorsement of Akershus.