I've got both the Kool Stop and the VAR I carry the VAR on every bike I have, and got one for my wife's bike as well. I don't know if it's lack of hand strength, or a tight combination (Conti GP4000 in 650c on various rims), but since I got back into cycling, I have been unable to mount a tire onto a rim unaided. The VAR works very well (just used it last weekend on the side of the road), but when I needed to put new tires on the tandem (Marathon Racers in 26x1.5), I needed the extra oomph from the Kool Stop (I'm pretty sure I could have eventually gotten them on with the VAR, but I had never used the Kool Stop and figured I'd give it a try).