I am an android fanboy, but the logic of the physical buttons on most devices escape me. The back button is great. No argument there. Easily the strongest feature of the OS. The home button is somewhat superfluous since long-pressing the back button achieves the same effect. The only useful thing it does is to bring up the task switcher if you long press it, but this should be the default action instead. I guess it is on some phones though, since physical button setups varies between most brands. The menu-button is being phased out in favor of on-screen options. I have no strong feelings about it either way. It works well in android 2.x, but I suspect android 4.x works just as well without it. Then there is the search button. Only reason it exists, must be because google is trying to impose a search paradigm where none is needed. All good apps have better and just as easily accessible search functions. Volume rockers and on/off/sleep switches, I consider separate and they work perfectly imo.