asmatt2,

I just removed the OS 120 Surpass II from my Showtime and replaced it with a Saito 150. If you just want to do pattern and "on-the-wing" aerobatics the OS 120 works great. My Showtime would hover but was left with very little pull out and that was on 30% nitro and it didn't seem to matter what prop I used. Since I'm flying at 5000' the hot summer days make it even more marginal and when it got above 90 I lost all margin and could hold a hover but not pull out at all. If you are lucky enough to get one of the lighter ST's and are flying at sea level the 120 may do the job but the plane really comes alive with the 150. Had to do a bit of firewall modification to get it to fit properly within the cowl but the effort was well worth it. Now it hovers at about 1/3 throttle with a 16x8 and 30%. Let's just say that "recovery" is not an issue but you do have to manage the throttle as it really scoots at full throttle when on the level.