Thanks for your reply.
I'm already on UK Crossfire Owners Group (Steve from Cheddar)

I'm happy with what I've done and at a reasonable cost of £250 all in. I wanted a bit more response in the low and midrange and I've got a not insignificant increase in torque exactly where I want it. Top end power which is never used is not so important to me. Totally agree re the fairy tale gains some remappers quote.

Cheers

Steve