I have had three os 40 LA and I lke the little buggers (I also have irvine's 53' adn 72's and a os 50 so I do like others as well) are uncimplicated and albeit not as powerfull... just remember ti back off two or three click from max rpm's whe tuning and they won't overheat

For this size engine I liek to use master airscrew SCIMITAR style props, the give you a better performance without the added weight and stiffness of APC's so if you're willing to try prop changes first try the Scimitar you'll like them