Functional but ...
I know that Patagonia has earned a solid reputation via their Capilene line but I don't get it. First ... a base layer, by definition, needs to be snug enough to fit under your mid layer which more often than not is a merino wool or fleece. Both of which are not exactly "silky" fabrics. As a result they grab onto what ever it is they are going over and or under. Capilene has too loose of a fit and it becomes a chore to adjust under your mid layer. Second ... while Capilene is very warm ... it gets very funky, very fast. I've ended up using my Capilene as a mid layer under Helly Hanson or Under Armour. Just depends on the conditions but in any case, Capilene is not my go to base.