I've had an OS four stroke for years, old 48 Surpass. I have also been flying plenty of Magnum FS engines. I just bought my first Saito but haven't gotten it in the air yet due to weather.

I don't have a problem with the Magnum engines. I have always been able to get them to fire right up and they have a good idle and smooth transition. I would say the only down side to Magnum is setting them up. I had a little trouble getting them setup until I had someone show me how to set the low end. It seems Magnums weren't set on the low end like OS engines out of the box. After I get the low end set they are great engines. I have five Magnum FS now, I wouldn't buy them if they gave me troubles.