Rapha, nice but a bit pricey?

Not bad. Its the sort of thing you chuck on for a downpour. So its not really designed with breathability at the top of the list. Its also not bike specific. So its probably too short at the back for normal heighted cyclists. Packs so small I keep losing it.

http://4.bp.blogspot.com/-ZbcLR5fNDMs/TnCX_IAt7PI/AAAAAAAAAKQ/0S7Z-5QEmtc/s1600/extra+layers.JPG
Looks like the Montane Featherlite velo I keep stashed in a pocket for rain. Very light and keeps the chill off, though I wouldn't want to use it as an everyday winter jacket.

There are some discounted closeout shells in odd colours around town in Snow+Rock and the like at the moment.. quite tempted. eg Arc'teryx Beta SL, North Face antimatter 40% off. Still spendy but almost justified if used 5 days a week all through winter.