I've decided I'm going to return my XLR. I've given it a couple of weeks, but not been able to settle with a mode which I can live with all the time.
The Eco setting makes the car easier to drive day-to-day, no doubt; but I found it dulled the response a little when pushing on.
The Sports setting was nicer in that regard, but not much different to stock in my opinion...but I couldn't get used to it, it still just didn't feel quite 'right'.
I went for another drive on Sunday morning and after fiddling with the modes and the fine tuning, I found that turning it off entirely and reverting to stock actually gave me the nicest experience. I don't doubt that the XLR will help a lot of other people, but I'm not convinced that it's fixed the underlying issues - even with the calibration, the pedal still feels like it should have a shorter throw, and there's still the slight stammer when picking up from low revs sometimes. I've no doubt that this gadget will help others by making that easier to manage - but I can get a bit anal about things like this, and I know for a fact that if I keep it, I will spend the rest of my time with the car constantly fiddling and adjusting modes. I think I'd rather live with the less than perfect stock throttle (which I'm at least used to) for now, until maybe I get it properly remapped at some point in the future.