Sorry mate, I was not being sarcastic when I asked you if you had kept wickets. I really wanted to know.
Well I have and I will tell you that its not very difficult to take a stumping of a medium pacer or even a fastish bowler if he bowled a good length and it came to the keeper without hinderance from the batsmans body, outside the off stum. In fact it is one of the easier deliveries to collect. The problem is if he pitches short and it bounces OR, worse still, if he bowls a full pitch or yorker, then it takes great skill to take it. Its like taking a throw from mid field.
The problem is when you get a nick and the ball deviates after hitting the edge or the body of the batsman. When keeping to spinners, its a different ball game. The spin, the trajectory, the bounce, the amount of turn everything veries much more from delivery to delivery than for a medium pacer. PLUS when you go up to a medium pacer, you generally have an understanding as to what and where he will bowl.
It looks spectacular, I know but isnt as tough as it looks, most of the time.