So my disclaimer here is that I have never tried Sonic before, believe it or not -- never!
This is probably not a location that you want to drive any amount of distance to get to, so unless you're in the immediate area...
With that said, food and service was fine -- food is reminiscent of an A&W Restaurant but with the wild-n-crazy drink menu that gets played up in Sonic's commercials. Service was pretty fast, and the server changed my drink order w/ no problem after I decided to not be boring and switched my Diet Coke to a watermelon slush.
And who knew that there is "Sonic Radio," complete with a super-chipper Sonic DJ?! I didn't get the chance to take in much of what was being broadcast to the parking lot though -- when it's 106 degrees outside, I learned that I take my food with the windows up and the A/C on...