I hated it (and not because of AVGN, I love James).
I hated a number of things: the mish-mash of storylines (Fleetway/Archie/games), the actor playing Robotnik (totally missed the mark on the character), the acting, the blatant cameos (love AVGN, and like Doug Walker, but they were too distracting), the fact that it's "SONIC" yet it's 90% Robotnik and GUN (sorry, "Gee You En").
The CG and real world footage just didn't mesh that well, and Sonic himself was horrible looking. There was no real story to be told, the chaos emeralds and rings were nowhere to be seen outside the titles. Overall I totally think the production quality and efforts have merit, but they combined to create garbage. Like, the Super Mario Bros Movie had big production values, unique sets and creatures, but its still a bad movie. Same here.