I was using the regular TT. I purchased an activation code and installed the latest beta (4.2.0.5767). I've noticed the beta is slow. If I click on a tab it takes a few seconds to go over. When i click on File and move the mouse down the menu it sometimes stalls. The same with fonts. I go to click the down arrow to scroll down to a larger font size and it will start off scrolling, then stop/pause, then start back up.
One feature I'd like to see is something I noticed in Artisteer. When you put your mouse over something new it makes the change to your template as long as your mouse is over it. For example, if I go to the page width and it's set to 800, if I put my mouse over 1000 the template will change to 1000px width as long as my mouse is over it. It's nice to see a preview without having to commit to the change at first.