It's definitively different, look at their website for the explanation of how it's built and you'll understand what it does. The chief engineer has a blog on their website that explains the principle. I also had a few email exchanges with him to get further details and when I got their design principles, it just made sense. The TOT is actually their entry level in their isolating power transformer line. The other models allow for lan based remote administration so you don't have to walk to the unit to do any settings. Those are for automated studios. The price is also very different, the largest component being the heavy toroidal transformer weighing 30 and above pounds.
My point is you need the two to make it as clean as it can be.
My point is you need the two to make it as clean as it can be.