We get this question quite a bit. I thought a blog post would clear it up. First, our cyclocross seals are not just for cyclocross. They are for anyone who rides in bad weather, races a lot or just wants to protect their bearings a little better.
Our cyclocross seal is a unique seal that while initially more "draggy" will break in and perform the same as our regular seals, while maintaining better sealing performance. When chosen, we install these on the outside of the bearing so that they protect against the elements. For some extreme cases, we'll also install them on the inside seal as well, but most of the time our normal seal is fine there.
They are really a great seal and we find more and more customers choosing this option. The key is to ignore how the BB performs at first, because there will be a lot of drag. After riding it for a few hundred miles, things get really good and the performance starts to shine.
These are only available for our BBs.