It's great, software updates are done right through the phone app. Matter of fact when I got my bike and installed the WU111, there were three software updates to my components waiting for me. I think without it you have to hook up to a PC using some special cable or something (don't quote me on that because I'm not for sure. I just remember reading people having to bring their bikes to the shop in order to do it). The ability to tweak settings such as shift speed, synchro shift, etc... is pretty awesome.