Nothing wrong with the standard item, drives just fine! If it didn't I would have flogged it by now, and made a profit.
The Pogea clone ECU has been around for a while now. The best bit is that it can be swapped in and out in a matter of minutes. It's not a complicated 'piggy back' chip, it's a pure like-for-(nearly)like replacement.
The car is fast enough as it is - zero to sixty in 4.2 secs if you use Launch Mode - so I don't see the need for the chip in day-to-day driving, other than for bragging rights down the pub.