I've worn it in some pretty crappy weather and occasionally gotten damp in it. Sleeves seem to go first, or maybe it's just that I'm more aware of it as I usually wear a short sleeved base layer underneath. I've never got to the point where the wetness becomes a huge problem.
In reply to An Triubhas:
It's classed as showerproof/ water resistant. I wear mine a lot (climbed in it today) & tbh it has to be pretty vile to put a hardshell over it. For at least 8 months of the year (I live in the Lakes) its my go to top.