Charles R.wrote a review of Scarpa Booster Climbing Shoe - Discontinued Vibram XS Grip on September 16, 2011
Aggressive? yes and all the wonderful precision that goes with it, but since the 4mm rubber stops just below the ball of your foot, easy to open up and smear.
Comfortable!! Very snug tight fit, but good padding under the leather on the top of the shoe, so while responsive and tight, not pinching. even after a 4 pitch trad day my dogs weren't barking too bad.
As far as being technical, I prefer bouldering (though leading sport and trad is a blast also) and these crush.
Nothing bad to say, except I'm nervous on getting them re-soled do to the weird rubber configuration, but worth it to have such a comfortable, smearable super aggressive shoe.