Powerchips are good, but them £100 copied ones from ebay are not. I would not risk my ECU on a copied chip.
I had a Superchip that didn't perform that well on my car, so I sold it to someone who had no problem with it.
I had Powerchips one on mine, and that is the ones I sell, as I have no problems with them.
They are £275-£300.
I ran one for years no boost limit no rev limit 303bhp on std injectors and small turbo EEC4.
I have my old one for sale too