What professionals say about teeing the ball:

Golf Magazine

Tee it High or Low? The right answer could give you 18 more yards with your driver
"...Within each of the three handicap levels, carry distance for mid- and high-tee heights was significantly longer than the low-tee height, largely an effect of the higher tees promoting higher launch angles and less spin. The high tee height provided the most distance, giving the players an average of 12 yards more carry per drive than the low tee height."

The Sand Trap

What's the proper tee height? Half a ball, baby. Half a ball.
"The general rule of thumb for woods and metals these days is this: tee the ball up so that, when your club rests lightly on the ground, ½ of the ball is above the topline of the club."

Zander Golf

Max Out Your Ball: Increasing your launch angle and decreasing your spin rate will help you hit it farther
(Appearing in Golf Digest)
" You can hit your drives 15 yards farther than you hit them now, using your current ball and without marking big changes in your swing or your physical conditions....It can be done, Just launch the ball higher with less backspin."

LSM Golf

Tee It High and Let It Fly!
"Imagine a line around the center of the golf ball and the top half of the golf ball needs to be above the top edge of the driver."