Interesting to hear of a 1st ride opinion on these, having been racing on one for so long now.
Yes, you can whip them up to speed, though there will come some extra effort from aero losses as you approach and exceed 20mph.
As for the saddle sway, I have dealt with this gremlin all these years, but this season (CX) I was wanting to secure the front end of the strap attachment lower for better accelerations when sprinting off of the saddle.
I used stout zip ties to pull the strap down against the twin lateral frame tubes, which made the saddle a lot more taut.
Interestingly, this actually improved the comfort in terms of the suspension action, but also did away with the sway that gave the otherwise-stable bike such a jiggly feel, and my lap times had to have improved.
I didn't know who was still selling these, but curiously the two, older Cheltenham-Pedersens I've had both were bought from sellers in L.A.
Also, at some point the owner of Kool-Stop was the importer.
Glad to hear you like the Pedersen. Here's my current (ca.1980) racer, wearing road tires in this picture, so here at just under 28lbs:
And a blast from the past, racing Expert/Elite class of the opening round of the UCI XC series back when mtb suspension was still in a relatively experimental stage:
Suffice to say, these bikes are also pretty durable.