Both my wife and I are registered with Castlegate Surgery and have been with them for about 8 years. We both (unfortunately!) have cause to visit them occasionally. I have found it to be a pleasant, modern practice, its doctors and nurses friendly and approachable and advice/treatment sound. Inevitably the surgery is busy but I have always been able to get through on the phone, though sometimes after a bit of a wait. I haven't had a problem with getting an emergency appointment as long as I have called first thing. Routine appointments will take a little longer, and can (but not always) take 1-2 weeks especially if you want to see your own doctor rather than the next doctor available. Early morning and evening appointments (particularly useful!) are available. If you need to speak to a doctor urgently but don't necessarily need to visit, there is a "phone list" and in my experience I have been phoned back either same day or the day after. They run a very efficient free flu jab service in the autumn. Recently they have a had a a new computer system installed, affecting for about a 4-6 weeks most aspects of the practice. However, they responded well to the inevitable glitches and re-orientation to this, and as far as | can see they have now emerged out the other side better for it.
So in summary I find them not absolutely outstanding, but good enough and have had no cause to seek practices new so far.
Hope that helps.