Here are a few pics from the first run of Lisa's Fairymead on Sunday.
http://forums.mylargescale.com/members/1979-rwjenkins-albums-fairymead-first-run.html
The engine ran very smoothly right out of the box. We were careful to keep the speed down due to the "top heaviness" that Eric described. The springs are very soft, much more so than any other Accucraft locomotive I have seen. Even at low speeds, she did tend to lean a bit on the curves, but fortunately we didn't have any derailments. The slow speed performance was excellent. Although the full Stephenson's valve gear theoretically allows you to run in the "company notch", there are still only three notches (forward, neutral, reverse) on the quadrant to choose from. There is R/C in this engine's future, so it should be interesting to see how she performs with the valve gear notched up. I also plan to install stiffer springs.
I didn't time the run, but the fuel lasted a surprisingly long time - long enough to need to pump water into the boiler several times during the run, and refill the water tank once before the fuel ran out. The sight glass was generally unreliable while running, but when I started pumping water the bubbles would settle out and I could usually get a good reading.
All in all, she's a really great little engine that runs well and looks amazing. Well, actually not so little. As I pointed out to Lisa, she now has a larger scale engine than me, and I have a 3 1/2" gauge (3/4" scale) ride-on engine!