just wanted to add my 2 cents.
i installed these shock shields to my head ytpmp, and i love the feel i get from the rackets. it definitely mutes the vibration by a lot. i am very pleased.
before with the stock hydrosorb, i could feel the vibration soar through my arm on my forehands. now with the shock shields, its toned down a lot.
i have to say, it does increase the grip size but a noticeable amount (noticeable.. not a lot though)., you do lose a little bit of the bevel... noticeable, but not a lot. and you do lose bit of "raw feel" if you will, when making contact with the ball.
hmm.. one thing that i found annoying, is the application of it. here's my best to create an accurate description, lets say hypothetically the grip is 1 inch wide, the gel portion of the grip, is centered against the outer grip, and measures only roughly .8 inches wide. therefore, it leaves a little bit of the outer grip without gel portion. i wanted to make sure that the gel portion was consistent throughout the entire grip, so i made sure i did the right overlapping, but the outer grip (the extra bit on the outside) tends to fold in, and creates an uneven job...
also, i didn't like the look of it after it was done. it looked kinda like michelin man. but it doesn't matter to me, because i was planned to put an overgrip over it.
i hardly think those things mentioned are that much of a compromise compared to what was gained for me.
i have slight tennis elbow, and this helped a lot. definitely rec'd for those with elbow issues.