Kevin -- The Hawk Arrow II is a nice bird. We had a guy at Turlock Airpark (9CL0) in CA when I was working there in the early '90s that had one. I worked on it a couple times. Taxi-tested it, but never got to fly it. :-(
They fly really nice. Chuck did a great job with the control harmonization, and they have a big tail so lots of rudder authority.. Just really pleasant to fly and I love having a stick instead of a wheel. Very docile, no bad habits. Only downside is the light weight and wing loading. In bouncy air it's a rougher ride than something like a Cherokee. OTOH, you can throttle back to idle and soar. I've been in a thermal climbing 1000fpm with the engine at idle, flaps out and the nose pointed down.
John - that is a great pic. Looks like a Grumman Ag Cat. I too love the sound of those radial engines. Nothing like them. We used to have a duster at the strip I trained at that had two of them, one with a 2 bladed prop, and one with a 3 blade prop. On the two blade, when he wound it up for take off the tips would go supersonic and just create the most amazing ear splitting noise! Once he got up in ground effect, he'd back off a couple of hundred RPM to get them subsonic and I swear the noise level would drop 20-30 db, leaving nothing but that great radial roar. Now that's *power*.