How good do you have to be for blades ?
Im not sure if the question that the OP asked is quite accurate.....
I think that no matter what club is in your hands if your swing isnt right then the outcome is going to be wobbly.....I feel that anyone thats shooting over the 100-120 mark then i suppose you could argue that whether he would have a Blade,P C/B, GI or SGI that score would remain the same...I think the issue then gets a little complicated the lower your handicap starts to drop....
You could be a mid handicapper with a poor long game but a decent short game in which case blades from 7Iron through wedges may not be a problem for you to hit.
Most teen handicappers are probably moderate ball strikers at best and i know that from my own point of view i can hit the ball a long way regularly but i do have issues with my swing which i am addressing at the moment.....
If i can swing on a proper plane with more consistency then im sure that no matter what club is in my hand to a point i can hit it....I would say that if someone is wanting to play these then i would play with an iron first that gives a good level of help to my game so that i can get some confidence in my ball striking....Then i would dabble a bit with players clubs and see what transpires.
As for Blades i would probably shy a little from these but i would consider players/cavity backs easily....