I've got one and i think its quite good matt! R - Vit type 2 i think from memory.
It displays info from the ecu and you can set warning buzzer and lights on it to whatever, mine is for the tacho so its in a sensible rev range either way so i don't stall and look like a tit or if i'm ragging the balls off it. It does keep info like best top speed, although on mine if it engages from torque it can sometimes give a crazy reading, it once said i peaked at 319mph which is impossible. One handy thing i found is that it can diplay speed in MPH instead of KPH which is useful on our scamera ridden roads.
I have the manual somewhere, if you need any more info let me know.