Hey Stew, I happen to almost match (O-320 RV-4) your request! I just recently replaced my 3 blade Catto with a 3 blade ground adjustable Sensenich and can't be happier! I swear it's quieter and smoother than the Catto, which I wasn't expecting. I tested it back to back with the Catto at max cruise pitch (7 pin) and tested it again today at slightly less pitch (6 pin) and am very impressed. The best part is repitching without shipping a 6 foot diameter box across the country.
I'm going to make a stand-alone post in the next few days with full details, but here are the numbers for quick review.
Static RPM:
Catto 3B: 2180, 29.0"hg
Sens #7: 2070, 28.8"hg
Sens #6: 2090, 29.1"hg
(RPM/KIAS/KTAS/"HG)
8000' pressure altitude:
Catto 3B: 2770/147KIAS/172KTAS/21.7....2400/125KIAS/145KTAS/18.5
Sens.#6: 2690/147KIAS/170KTAS/21.8...2400/128KIAS/150KTAS/19.0
Sens.#7: 2610/146KIAS/170KTAS/21.8...2400/131KIAS/154KTAS/19.9
6000' pressure altitude
Catto 6k: 2800/155KIAS/174KTAS/23.4....2400/128KIAS/146KTAS/20.0
Sens.#6: 2730/153KIAS/173KTAS/23.4...2400/133KIAS/150KTAS/20.3
Sens.#7: 2610/150KIAS/168KTAS/23.5...2400/138KIAS/156KTAS/20.5
I think at #5 pitch pin I'll probably get near the Catto RPM and do a knot or two faster than the Catto, but honestly I'll probably go back to #7 for cross country flying and use #4-5 pitch for KC Flight airshows (so I'm not whining as much for lead to "gimme one") or backcountry flying. I don't think you can go wrong with this prop.
Fitz
RV-4 - 160HP O-320 - Sensenich GA
KC Flight Formation Team