RE: 4 strokes
When Global dropped the price last year so you could buy the Magnum 91 for $150 (even less with various promo codes), it was easy to justify buying it versus spending $250 for the OS or $265 for the Saito.
At 190 vs 250, I'd choose OS.
If I actually needed an engine today the choice would probably be Saito because the OS is currently on backorder.