I currently use an Oxford magnetic tank bag. It's a small enough for those days when you just need somewhere for your spare specs and wallet but it also expands. But it is the magnets that are my concern.
No matter how much you wipe the base of the bag, the magnets will start to scratch the paint. So before the Spain trip last summer, I started to look at the Givi tank-lock system. In the end I shelved that as I had only recently bought the new top box and and inner bag!
So with Spring approaching (sometime any way!) I decided to have another look. Prices don't seem to have changed much, and when Googling, the overseas shops seem to have prices about 20% cheaper than here. With postage taken into account they are still cheaper.
So, I ordered the Givi 3D604 bag from Motocard.
Delivery takes about a week and that's okay as I don't intend to use it for a while.