The Griffins serves quality meals and I would recommend it for a decent pub dinner. I have had barramundi and swordfish there and both were quite good. Friends that I've been there with have enjoyed other meals including salt and pepper squid and the schnitzels. The outdoor dining is pleasant in the warmer weather and the atmosphere is nice inside as well.
The service at the Griffins is also quite good and I'm always grateful when you can get excellent coffee at a pub (as you can here).
My only grumble with Griffins is the lack of a lunch menu. While many similar city pubs offer cheaper lunch options, Griffins effectively serves dinner twice a day. Consequently there are many better value choices for lunch around Adelaide.