The series is just getting started. I read the comics as they come out and am up to date with it all. The series right now is in the begining of chapter two, and the comics are on fifteen.
Some things are different, but its understandable as to why they did them. For example, Shane was dead by the time they left their first camp where Amy and Jim died, but for a series his character makes things a bit more interesting. They never went to CDC in the comic, and Merle, Darryl, and T-Dog are original characters not included in the comics.
I have faith in the series. The character development for some is already an entertaining aspect.