Rode the Cog on Saturday. Plan was to do the North Conway Scenic, but schedules did not allow so we did this instead. Having never done either, I was very happy with this opportunity.
Booked tix on the phone Saturday morning -- we didn't have access to a printer or good internet connection, so Ma Bell served us well. Reserved two seats on the 11:30 departure (only the first run of the day, at 8:15, is steam, rest are bio-diesel). Arrived a couple minutes after 11 and picked up our tix, lined up at 11:15, and boarding started right around then. Last boarders got on the train at around 11:25, so even though they tell you you must be there by 11:15, there is some wiggle room.
Good trip up, brakeman was quite entertaining. We were in the second row (facing up) on the left side of the car (the "scarier" side, per the literature), and enjoyed the ride up. Got into the clouds in the final 200 or so feet, and there was nearly zero visibility at the summit, with winds of 50-55 mph. Walked around and saw what we could see, then caught the 1:10PM train down. Got on the left side (facing down), row, up against the back door, so had a great view of the tracks and switches on the ride down. Brakeman announced trip would take 35 minutes ("unless something goes wrong, in which case it could be just two minutes"), but actually took closer to 50 minutes. Not nearly as entertaining a ride, but there is less to see going down, and he was working the brake wheels (in theory, at least).
We checked out the steam engine and headed back to our base.
Not sure it's worth the $55 or so/person fare (in other words, we won't be returning soon), but the brakes on my Subie were pleased we didn't take the Auto road, and we did enjoy the trip. Maybe if the clouds had lifted we'd have a different feeling about the value.