Generic maps get a bad rep but they all started out as one off custom maps.
Generic maps are those that are tried and tested and give you the best blend between performance, reliability and economy
Its the car and its components that are always the weak link and a remap will quickly find these
As said AVOID Ebay; you need to find a tuner who has expericence and a good reputation
Black Smoke maps are ok BUT you need to buy a Galleto cable and there is always the risk it will brick your ecu and turn your car into a very expensive brick
Tuners like myself use relaible equipment, that should anything go wrong, we have the ability to recover the ecu and get you going again