Well, I actually bought it yesterday, but I was too busy playing with it and then watching the TdF highlights on the pooter to get round to reporting it here: I have just bought a second hand flat-barred Hewitt Cheviot.
I rode it to work this morning and it is a delight: no more sluggish, it seems, than my usual commuting bike, but it will need a few further tweaks to get it ready for the DunRun and future tours. Handlebars have been cut down slightly too much for my taste, so the outer edges of my palms press against the bar ends, and there's a bit of very slight unhappiness in the drivetrain that I will need to diagnose.
But the Mahura HS11 brakes are a joy to use. It'll be interesting to see how they work when the bike's loaded up and I can get it to the top of a decent hill.