As a guitarist, I would criticize Doug the same way I criticize Slash. A great guitarist once told me--and it seems obvious now--that what you don't play is as important as what you do play. Just like a singer doesn't vomit all over a song without taking a breath, neither should a guitar player.
Now, I like Slash as a player in many ways, but one thing I don't like about many of his solos is that he tends to just vomit all over it without giving room for it to breathe. Dirty Little Thing is a great example of what I am talking about.
Obviously Doug isn't the same category of player as Slash, but he is a very busy player. The other thing that annoyed me was he tended to play in a very metered way. For example, in the above clip of Paralysis, lots of what he is playing is just straight eighth notes. He did a lot of that in Scott's songs, straight quarter or eighth note melodies on guitar.