Just a thought, and like everything else posted here this isn't for everyone. I really enjoy wearing a pair of Muck Jobbers (in the cold, snow, and rain) and riding with Power Grips year round. I really don't feel like I lose a ton of efficiency (although I'm sure I lose some). I feel the Power Grips are far more efficient and more comfy than toe cages, and the Mucks keep my feet really warm with some wool socks. They're also and definitely dry for all your wet conditions (almost rubber everything).

Not to brag, just to let you know what conditions I ride to work in: 40 miles daily in the Pacific NW. I also rode in this configuration in Kodiak, AK and Traverse City, MI for similar distances and was quite successful daily no matter what. I also ride a Surly LHT with waterproof paniers, so I'm not breaking any land speed records either. It's probably why I don't mind the loss of efficiency so much.