Having been doing a bit of stalking in pretty crap weather lately, it still amuses me that people don't believe I can be warm, dry and comfortable while wearing so little above the waist.
In any and all conditions for active stalking, I simply use the Buffalo Special Six shirt. Nothing underneath, nothing over the top....even down to -10. If I plan on sitting out over a clearfell for several hours in sub-zero conditions, then I just throw my Buffalo Parka over the top. This two layer system will quite happily deal with sleet, rain, snow and even allow sheet ice to form over the top with no ill effects! The coldest I have sat out for was -14 for five hours and I was quite comfortable....and none of it is waterproof!!
I'm lucky to have the Harkila Pro Hunter Jacket, and while it is a cracking bit of kit, I just seem to leave it in the truck more and more these days due to its bulk and weight.
I meet very few people outside of the climbing fraternity who wear Buffalo, in fact the only stalkers I have met wearing it have been FC Rangers and I am surprised more stalkers have not yet discovered the benefits.
If you have an 'outdoorsy' type shop near you, then I highly recommend you check it out.
If you are intrigued, then this site describes how the system works much better than I can: