I’ve had a couple of pairs of Impacts and really like them, apart from the “sponginess”. It’s pretty wet a lot of the time where I am and they do absorb a ridiculous amount of water and take ages to dry out. I’ve sprayed mine with silicone waterproofer but I don’t reckon it makes that much difference really.
Some people say the insoles fall apart in the wet but I can’t say I’ve had that problem with mine – it’s just annoying that they take so long to dry after a wet ride.
I don’t think there’s really a proper solution, apart from getting some less padded shoes. Someone on a unicycling forum I frequent knows one of the 5:10 people and when I had my first pair I asked him why they didn’t use closed-cell foam to help those of us who don’t live in California. He claimed they already do – I’m not convinced though.
But until I find something else as comfortable and grippy I’ll be putting up with the sponge effect in the wet.