Finally, I got the tailwheel set up and had another short flight yesterday.
I built the tailwheel as per plans - i.e. free-castering. At low speeds it was still quite a handful, but much more controllable than the skid. At high speeds it was quite well behaved. I haven't got even an intuitive grasp on how tailwheels 'work', but despite being free-castering it clearly gave you a lot more yaw stability than the skid.
I think I have the same brake pedals as ExSpeedBird and yesterday, rather than starting on the rudder pedals and then moving my feet to the brakes as I got slow enough to need them, I did so well in advance covering each rudder/brake combination with the respective foot - you reach full brake travel at the end of the rudder travel so can use both together. It's not an ergonomically pleasing system, but it is workable with practice and with brakes that are reasonably progressive.
The other slightly alarming observation was that at idle there's now enough thrust to start the aircraft moving gently forwards - with the skid this wasn't an issue, even on tarmac. On grass it's still OK, but methinks the chocks now need a piece of string so I can pull them both out at the same time from behind the wing.