Wow. What school do you attend that would offer Systema? I take MMA classes, and individual Thai boxing classes in addition, and it seems very useful. But Systema is what is used by the (made popular by Call of Duty) войска специального назначения (or as you may know them- Spetsnaz) and can be highly dangerous to whoever may choose to pick a fight with you 
Try it out! Thai schools are..a dime a dozen. Systema ay be a once in a lifetime opportunity. Or at least from what I have gathered. I do know there are schools around, but they seem to be difficult to find for myself :D
