In TA, neutral has to research the terraforming techs to get instant terraforming. In DA, you only have to select the alignment and all your planets instantly terraform, unless something has changed since I last played DA. It's been a while. Anyway, that can make a big difference early game when you don't have the research horsepower to make light work of getting through the terraforming techs. Also, I think the morale bonus is a bit higher in DA, but I'm not sure about that.
Regarding the MCC, I've mentioned it before in another post, but I do think it's more powerful in TA than DA. The econ bonus in DA is significant, but the influence bonus in TA is actually more effective for me.
One note, I'm playing with a mod I did for myself that changes TA quite a bit, makes it more "DA like". I haven't played a stock game in a while. You should take a quick look at it, shouldn't take long. I'd like to hear your opinion. I think you mentioned you downloaded it already, but here's a link to the original post;
Merry Xmas, BTW