The M&M3 stuff I've seen come out so far has been quite good - interesting characters, great art and great plot hooks. This team looks like it's going to be quite interesting to read about as well, we've already seen their stats, so it's nice to see their backgrounds as well.
However, there's something not quite right here. The description says it includes writeups for the entire team, but the download only includes one character, Dragoneye. That writeup is good, but it's not what was promised - the entire team. As such I have to give it a bad rating.
The writeup for Dragoneye is itself quite good, and I would give it a much better rating if the entire team was included or if the download was labelled as "Dragoneye" rather than "the Sentinels."
[Update after having gone back to the page]
So apparently the issue is that each file was uploaded individually, but when you hit the "Get it now" button, you only get the first one. Seems the issue is a combination of RPGNow's code and an odd choice on Green Ronin's part. It would have been much easier and less confusing to just zip the files together into a single download.
Increasing my rating, but still knocking it down due to the download experience.
[3 of 5 Stars!]