Another Specialized pump head hater here. Just awful. I bought an AirTool about 9 years ago and could never get the head to seal properly without a lot of fiddling, and it liked to bend Presta valve cores too. I finally replaced it, first with a Silca then a Topeak dual-head. The rest of the pump has worked great though throughout all that time. Recently I went on a biking trip/vacation with a friend. He brought his brand new Specialized pump, and, wow, nothing at all has changed. The Specialized head is still finicky as hell. He seemed to have the hang of it though, and he's a noob, so there must be some technique to it that requires you to unlearn how every other pump head is used (unscrewing the Presta nut only part way seemed to help a lot, IIRC). I ended up using my Road Morph most of the time on that trip.