I'm not sure about the 2.2, but there are a few of us who've tried it on the 1.9
In a nutshell, it's great if it works.
To expand on that - it can pan out as one of three scenarios:
1) You'll get loads more power and torque and the car will go like a dream
2) You'll get loads more power and torque, but the car will occasionally throw a fuel injection wobbly and leave you with none of either. You tweak the box down a bit and end up with a lower but still useable amount of boost.
3) Like scenario 2, except that the car still complains even when you've tweaked the box to quite a low setting. You hit the point where you have to tweak the box so low to avoid the injection faults that you find there's no noticeable difference in the way that it drives with the box to the way it drives without.
Fortunately, most people who try it experience one of the first two scenarios. A few of us (me included) have ended up with the third one
There seems to be a lot of variation between supposedly identical engines, so you really have to try it for yourself and see how it goes.