I see over 8 doctors in MMG (I'm a caregiver), and in my experience, the doctors are always quite knowledgeable and friendly.
However, MMG has a very strict late policy. If you are 10 minutes late or more, don't expect to see a doctor. They will make you reschedule without regard to your excuses, calling ahead, or how long you've waited for that appointment. (I was 12 minutes late to today - because I drove to the wrong location first - and I had waited to see Dr Upchurch for 5 months). Don't expect compassion even if you cry. :(