I have th Durametric tool. It's currently the only reason I can drive the Boxster right now since it can read/clear the codes without turning the engine on (having trouble with a P1502 code currently). It reads the airbag, alarm, A/C systems along with the regular OBD II codes. If you use it for diagnostics where you have a wireless internet connection, you can even click on the codes it pulls and go to their website where it will tell you what other people have done to fix that particular code.
It's a handy tool I wouldn't want to be without, especially since it was under $250 delivered.
