Having read a good deal of the reviews on Amazon before watching this season, I was fully expecting to be disappointed. But that fear was completely unfounded. You'll notice a number of minor changes this season, but most of them are very much overstated in the majority of the negative reviews I've seen on this page.
There are fewer episodes in this season, but the episodes are also twice as long. The curses are no longer bleeped by that awesome guitar squeeling, but there's also a great deal more cursing in this season; so I imagine that much bleeping would have just become annoying. And it's surprisingly refreshing to not have any edited language this time around. Lastly, while the storylines are as amazingly well-written as ever, the majority of the episodes don't contain new tracks or concerts. You'll notice there's plenty of musical material however, but the focus does seem to be much heavier on the story side of things within season 3.
The core of the show you undoubtedly adored in seasons 1 and 2 is still very much intact. Metalocalypse is still clever, brutal, and hilarious; the way that it's always been. Some reviewers have insisted that the show took a completely different direction; leading me to believe that the band was undergoing changes to its lineup or that Ofdensen was really gone for good, in an attempt to keep the scripts fresh. But again, there's nothing like that here. This is still Metalocalypse.
The only real reason I'm giving this season a 4 instead of a 5 is because of the fact that so many of the more comedy-laden tracks were incorporated here, while the metal tracks weren't given equal showcasing. Still, aside from that, season 3 was fantastic! Just like with the first two seasons, once I turned the first episode on, I didn't sleep until I'd finished them all. Highly recommended.