I like TA a lot because it has some nice features over DA, but DA is probably more consistent as far as how the game plays. TA has some trouble with the AI doing strange things sometimes. And yea, things move slower in TA.
I did a mod for myself that changes all the tech trees and a lot of other things to make TA play more like DA. I've been playing it a lot. The changes are pretty radical, but it makes the game move really fast and the AI really flys with it. Here's a link to the the post;