Ive had my cup superchipped. Some observations:
Feels gutsier lower down, ie 3000-5000 revs
Less noticable VVT crossover
Can feel a little breathless beyond 6500
RR showed only 3bhp increase, but 10lb ft; bear in mind that this was done during the really hot period in early august - it was 91 degrees F (before was 164bhp and 144lb ft, after chipping was 167 and 154)
Easily reversible, as its a simple flash of the ECU - mind you, you need to take it back to the dealer who chipped it and pay £50ish!
Comes with a years warranty
Economy unaffected, ie still 35-37mpg however hard I drive, & had 42.7 on a round trip of 600 miles.
£293 inc VAT and flashing = no more expensive than R-sport
Cant say if its better or worse than R-sport ecu - so I respect Chris-n-Nics view above.