I've been using this mount with the Universal Spring Loaded Gadget Holder for Electronic Devices for a couple of weeks now with my HTC EVO. GREAT idea and design. Plenty of room to install on my bars and swivels enough to get my HTC where I need it to see the GPS and play my music.
It's a really good good mount. Feels strong and strudy but only if you install it on a straight (not curved) part of your handlebar. It comes with rubber self adhesive spacers you should cut to fit your diameter. If installed correctly it will feel strong and solid without any flimsiness. The only concern could be the strap end sticking out (as shown on the photo).