In extreme conditions (I think the V 100 will meet that criteria) the concepts of "waterproof" and "breathable" are relative. Some damp will always find its way in, and some condensation will be generated because your body is working hard. You may not be aware of this, but it is happening.

The layer(s) worn underneath are also very important. You need to consider the whole system, and not just the outer shell. Many modern base layers use excellent synthetic materials, which remain effective even when damp.

I think the real question is how comfortable you feel, not how to stay "dry".

For what it's worth, my kit list was: Mountain Equipment Paclite jacket (excellent),North Face over trousers (light and comfortable, but not totally dry inside), Salomon Goretex shoes and Bridgedale socks and liners (wet feet, but reasonably comfortable in the circumstances). Maybe I'll try waterproof socks sometime, but reports seem to be mixed. I understand the recommendation elsewhere for Paramo waterproofs, but they're too warm for me. A wicking base layer was all I needed under the Paclite most of the time. In the nights I added my favourite piece of kit: a Paramo shirt that I've had for at least ten years. It works as a thin fleece or a wind-resisting outer and I love it! 48 hours after finishing I still have sore feet, bruised more than blistered I think. I wasn't quite on my last legs at the finish, but i wouldn't have fancied a second lap! Tim.

If you managed to stay dry during the Valleys 100, what gear was it that served you so well?