If you ever want to run Mogas or unleaded ULP, the you’re likely limited to 8.5:1 compression ratio. Handy if you end up somewhere that doesn’t have 100LL available, or you just don’t want to fill your engine with corrosive lead bromide salts. If you build a light aircraft, even 180hp in these things feels like a boatload of power and you’ll never have to worry about not having enough HP to get out of somewhere short you got into.
Tom
RV-7, IO-360 M1B, Hartzell BA