mini refers to a slightly smaller edition of the marker, automags are completely mechanical.
R/T is response trigger...just like Tippmann
68 is the original trigger and valve configuration
The only electro is called - E-mag- If you can find one at a reasonable price they're kick-a, if you can keep it working. They are electro primarily, but if the battery dies or you change your mind, you can flip a switch and shoot it mechanically. Mag was way ahead of their time, too bad they crapped out financially.
Come to a night game and I'll show you what it feels like to get shot by one.