Before jumping the Viper I put about 25 jumps on a V5 to get comfortable with the tail. In addition I had a friend inflate the suit with a leaf blower so I can do a few practice pulls and "feel" the suit on the ground.
It is a big suit, so as usual it's important to be relaxed, let the suit fly you and give very, very small inputs. I've had no issues turning (I turn by pushing down the arm & leg a bit) and no instability issues, just fatigue in the arms after a while. Like the V5, the faster the better and the more fun it is. The pull is no problem, but I recommend to do a few practice pulls on the ground as described above.
I usually only jump the suit at the beginning of the day when I am 100%. I have not jumped it from a Balloon as I want to make sure I know the suit really well before I do so. In my opinion the Viper is for people who already know how to fly their body in any axis & orientation, just having jumped big suits is not enough in my opinion, but I tend to be on the conservative side.