RE: 4 stroke selection OS, Saito or ???
Some planes need weight on the nose and some do not.
The Ultra Sticks do not, so if you are the type that "hates" adding ballast take weight into account when you are choosing.
I have had good experiences with Magnum, OS, and Saito.
While I like OS and Saito better, it sure is hard to beat the Magnums when you can catch them on the super sales that come along a few times every year.