I have started replacing my merino base layers with Alpaca when I can find it. It is 3-4 times warmer than wool and seems to have a broader temperature range due to the hollow fibers. Great for socks too. The other I like is the Patagonia which is the best of wool and synthetic combined.
The Natural gear fleece is very wind repellent with out a membrane. The membrane I think defeats the purpose of the fleece as a mid layer.
I always carry rain gear and if wind is a problem I wear that over all but most of my jackets do fine without it.
