I am the proud owner of a Saito engine, the older style with the choke. It idles at around 1900 - 2100 RPM and just keeps running. It was a little finicky during break-in, so I would recommend running around four tanks through it on the ground. Saito engines are TOP QUALITY.

The four star 60 flies better than the 40 for the reasons your instructor suggested but the 40 size is great too.