Right finally job done. Swapped the sensor today and its all running sweet as a nut again.

With the new coil, leads, sparks, oil and filter i would even say better!
Had a bit of a nightmare though, after an hour of trying to figure out why the sensor wouldn't seal the water in anymore I had to thank rubjonny who confirmed that there should have been a rubber o ring in there.... DUH. In my attempt to change it without draining the coolant the water pushed out the o ring when i took the sensor out. I so concerned with all the water coming out i didn't notice the o ring jump out and lodge itself behind the distributor.

Cheers Jonny!
So morals of the story -1. I don't trust GSF temp sensors (VAG one was 9.52+Vat) and 2. Don't lose the o ring!