Went through a few setup's until I was happy. Tried the official charger and official wireless battery cover.
Worked brilliantly, but the back was a little too heavy and thick for my tastes. Tried various Qi pads, settled on the official one as it had the best positioning, the others you have be careful to align the coils just so. EP P100IEWEGWW, paid £33 from Amazon.de
I found one of the Qi receiver designs ran a little warm, eventually used one from a Chinese supplier 181153769906 £7.20
To get it dead flat, had to mill a little material from a stock battery cover and now use it with an SGP Neo Matrix.