After my "duff waterproof" thread I thought I'd better test it to check it was actually deficient. (I'd got wet under it after a leisurely 20m spin in light rain.)
I had to ride into town again so I wore it with the same jumper on underneath, rode at roughly the same pace, on a cold and crisp evening. Turns out that was enough to generate a decent amount of sweat! (less than before though, which I presume is due to the dryness and coldness). I then wore it in the shower, and it appears to be waterproof.
So it seems (a) DWR lasts **** all time and (b) breathability is still inadequate (albeit this was a £100 Jacket)
(a) - treating and tumble-drying still the ways to go?
(b) - do expensive fabrics breathe well enough to make them worth buying?

