i had one & i took it off 'cos i couldn't get the mixture right low down. not directly the fault of the techlusion, more the required disconnection of the lambda probe.
others appear to have not had this problem, or have not noticed it perhaps?
easy to adjust otherwise, though you'd need a dyno to do it properly.
oh yes, mileage was down too. it would be really wouldn't it, all it does is add fuel.
roughly 185* miles per tank down to about 165.
*no CCP fitted.