I thought I recall that Chuck Yeager set some records in the 400 many years ago- not sure exactly what they were for.......
I think he set a speed record coast to coast. The 400 was very fast and could go to FL410. I bet the 331's just sip fuel way up there.
Back then Piper advertised jet speed with turbo prop operating cost. It all sounds good until you pay for OH on the props. I'd still like to fly one---for a while.