Well, the rain buggered off just before five, so I managed to spend a very dirty hour in the company of Max the MTB.
Moving the saddle back made things much more comfy and I had a blast. The bike is very surefooted on roads slimed with mud and loose gravel and feels very "planted". It's exactly what I was hoping for.
Front mudguard is shite though - that definitely needs tweaking as it was flicking mud over my feet and the downtube. Rear one is spot on, as my bum is squeaky clean!
Still in two minds about the Selle SMP saddle. I'll give it the benefit of the doubt for now, but I'm leaning towards flogging it here on CC and getting another Charge Ladle.
The post-ride

did go down a treat though.