I have only gotten a few chances so far to use my new boosters, but I really do love them. They are a great shoe for bouldering which is what I bought them for. There is nothing the boosters aren't good for when it comes to bouldering with them. BUT I must say that my heal doesn't fit perfectly into the heel pocket of the shoe because it is so deep, or maybe my heel is just a weird shape. Overall they are an awesome shoe. FYI my running shoe size is a 45 and I got the boosters in a 44.