I frequently find myself navigating to a different preset from the one I'm working on to find out how a global variable is treated there - for other reasons too, but this scenario gives the general picture.
When I'm done checking out this second preset, I have to navigate back to the first, but often find I've forgotten which one it is. Of course a pencil and paper could solve the problem, but, as with many other things in life, I'm prone to be a bit undisciplined, and forget to do that too.
A nice feature to have in MT would be a hotkey or menu item that returns one to a previous preset. This is kind of along the lines of another suggestion I made a while back, to be able to navigate to a preset and translator by clicking on a reference to it in the log file.
Gabriel