the boy martin used is in motherwell now, its powertune scotland, he done my c4, tbh hes much the same as angeltuning, just plugs a PDa into the obdII socket and uploads a ecu flash. but from what ive heads angel tuning are very good. the boys over on C4owners.net sing their praises i'd say i'm in the minority that havent used them.
Joe who is powertune, is a really nice guy and did reflash the car with apparently witha stronger map after the Falkland RRday which said i got about 12bhp and 8f/lbs of tourque, roughly a 3rd of what a remap shouold yeld. but tbh the new map made hee haw difference.
the 136 units pug use dont remap that welll i mean they still go up to 160 odd bhp, but the ECu's they use only let you adjust the fueling not the boost or anything else iirc.