Have a few hours on the poor mans mustang.
Same wing section as a Mustang to I believe.
Fuel against speed they are pretty uneconomical.
I've also been told that at the same speed as a 250/260 they burn the same amount of fuel, but when you want to go faster you can.
I read somewhere the 400 was Piper answer to turbo charging. Put in a big donk that still allows enough power up high for good performance. Good TAS without the expense/complication of a turbo.