Thank you all, just came across this video which did some good controlled tests, whats interesting is the results at the 6:10 mark:
In a nutshell, under 10 degrees the all weather tyres perform better in the rain, looking at London weather averages, that would be 4 months out of the year (Nov to Feb) the all weather tyres should outperform, rest of the year they are still not too bad but do lag behind summer tyres a bit.
Trying to decide what to do now, if I go for all season i'd have to replace all 4 tyres, my rears still have 5 to 6mm left I think so that feels like a bit of a waste, would welcome thoughts from the members here 🙂