i have used both wool and synthetic base layers in cold wet climates, namely new zealand, for the last 5 years. i found wool dries slower and is less durable but doesn't get stinky and is marginally warmer.
poly dries much much faster, is alot more durable but tends to get more stinky.
i've come to the conclusion, at least in cold wet climates, that the primary role of the base layer is to wick moisture from the skin and dry as fast as possible. it is not a layer that adds warmth via insulation. that task is performed by the outer insulating layers. where the baselayer fits into the providing of warmth is it's ability to dry fast after a big sweaty push up a mountain before adding extra layers for warmth, therefore not trapping a wet baselayer under dry outer layers.
i know wool insulates when wet but i've found that, at least in NZ conditions, dry synthetic under proper layering is warmer than wet wool.
no sense in wet wool under a down jacket for example.
i like wool too and i find it's better suited to colder drier conditions where there's less physical exertion.