I own a first-run Super-T1. It is a fantastic device that will certainly outlive me. My favorite features are the locking button and the adjustable throw of the button. My last order of CR2 batteries - I only vape at 6 volts - were slightly longer than CR2's I ordered previously. A simple change of the button throw adjustment was needed to make these new cells work the way I wanted them to.
Even without the locking button, the new Super Six looks like a killer single-voltage device. The Super-T line is best used at one configuratio, and it does this very, very well. If you want to run multiple voltages, only the Super-T1 could do that. In my opinion, once you pick your favorite voltage, you will continue to vape at that voltage.