I think one big reason C3 is just not nearly as good as the previous two campaigns is that Matt wants to describe and narrate every single thing to the most minute detail. Like in the last episode, one of the party used a spell scroll to make the party scry-immune. He spent a full forty seconds describing what it does:
You finish the incantation. All of you suddenly watch as this dome around your crew of slightly mercurial reflective energy swirls around, and then it encloses in, like a specter of a bubble that suddenly closes. As it washes through you, you feel this faint chill across your mind. As it fades, you get the sense that there is a protective enchantment that sits within you for quite some time. The scroll burns away in your grasp as it completes.
That's fine in a vacuum, but he does this shit so constantly that it really drags the pace down for me.