1. Any class that is seriously dangerous if mind controlled should NOT take the risk for some damage. No-brainer for sniper.
2. You won't ever be taking two shots at anyone and you need to be using height in this game ALL the time. Another no-brainer.
3. You will be killing. A lot. You also should be the safest person in the squad. Makes this ability a no-brainer.

4. Don't/shouldn't ever get close enough for the other to work. Not even close.
5. Fast recovery is worthless and muscle fiber OP. The cost is steep but by mid-end game I don't die and have all the meld I could want. Not even close.