I recently found a great deal on a racechip ultimate tune for my 2012 r56 mcs (n18 variant), however I've seen a lot of negative results about the chip for mini coopers. Does anyone have any advice or opinions about this chip and if it's worth $300 cad?

 

Never even heard of that brand.

There are very few tunes that are known to work with this platform (especially the N18 engine specifically) and it's safer to stick with those. Burger Tuning JB+ piggyback, or Manic/RPM flash tunes.

 

We've tried them and other piggy back units for the N18. Save your money for a real tune as it will net you more power for the buck and be real as it will adjust the boost, timing, fuel and so on in the ECU rather than making fake signals to try and trick the ECU into making more power.