I'm new to TT, so let me give you my impression so far.
There is a blank template that allows you to build the template from scratch, so just about any design you have seen can be duplicated. This is really useful if you are building for a client who already has a coporate identity with logos, colors, etc.
I would say this is as close as you'll come to a pro themes builder if you don't know coding.
For widgits, they use a unique approach that allows you to add a widget area just about anywhere in the template. What you put in that widget section is of course selected in WP after applying your theme. So you can't actually build a widget if that's what you were asking.
Hope I didn't step on any toes here, like I said I'm only 4 days into TT, and these are my impressions.