I will be ordering my GP Super Stearman early next month and am tossing up on a similar choice of engines.
I had been thinking about the choice between an OS 1.20 w pump or a Saito 1.50
The two are similar in price and the Saito is slightly lighter.

What is swaying me towards the OS is the fact that it gets mounted inverted and I was thinking that the idle might be more reliable with the pumped motor.

I would be grateful for people's thoughts / comments on these two engines.

What other impressions do you have from the kit?

Given that this is a "first release", have you come across any problems yet?

Regards

Ari Palsson