I would absolutely love to have an OS four stroke. I personally would go without the pump as I have seen how they upgrade their engines and owners are no longer able to find parts for their outdated pump. A pump is great for applications where your tank is either at the center of gravity, or in an awkward spot. They make aftermarket pumps for stuff like that for $30-$60.

I have bought 4 OS two strokes in my first year of flying, and while I never want to spend the extra money for OS, I'm always glad I did. It doesn't take long before you forgot how much you paid and you realize how much you love your OS.

I think OS comes out to be less expensive than Saito with the Tower discounts, especially if you are in the super savers club.