If you watch the top players, when they barely get to the ball, the ball bounces WAAAY HIGH, from the conti grip, and the lack of body/hand control on tough serves.
No way, can you block a fast serve back using your normal grips. Underspin is needed, and part of "blocking" the serve back.
An error to high is much much better than an error into the net. Returning big fast serves is all about limiting the damage from your errors.
But whatever, why do what Federer, Nadal, DJ, and Murray do? Use your own method, it's worked for you..