stealth use dastek and iv heard some dodgythings about amd fiddling the tranny loss to gain phantom bhp personally id goto stealth but having said that iv just had an off the shelf powerchip fitted by collins perfomance engineering in congleton cheshire for £176 all in took about 1 hour and initial reaction is it seems a bit quicker deffo smoothed out the flat spot at 4-5k revs due too the schrick and also the mpg stayed suprisingly high but that may not last lol