I took a Scottish friend to St. Andrews for his birthday last year and to see his college friend perform in Les Miserables before it closed (he was Jean Valjean, actually...very cool).
Anyway, we had a very nice meal. The online reviews for St. Andrews were excellent. I thought our meal was very good, authentically Scottish and what I had expected. Don't expect anything spectacular and you'll be pleased. The service was also pleasant, but we were there after a Sunday matinee and the restaurant was very quiet.
The bar area was great. I remember thinking as I left that it would be a great place to come back for a beer - they had many, many imports on tap.