I find this series to be a great take on the Transformers universe. Both Autobot's and Decepticon's are greatly equal in strength, and it has a more realistic atmosphere with being darker than the previous Universes.
The voice acting is done wonderfully, and it's great to see Peter and Frank in their original roles. Something that G1 never had was the power that this one does. Of course, we know being an 80's cartoon for kids, there were obvious set backs for that reason. Some debate on the fact that Prime isn't a kids show, but I believe with the world today, it suits well for children to realise consequence and death, and it's a bonus for us older fans.
Visually, I think this series has it all. Great designs, and great CGI (for a cartoon). The character development is well portrayed, and, of course, they link back to their original 80's personalities.
Overall, I think it's by far the best series up to date, aside from G1--but that's because it's the ultimate classic.