I had one for a little while with a OS 1.60. I should have put a pump on it! I got about 3 maybe 4 flights and then the 1.60 quit on me and that Pitts sank like a rock!! I was running HS 625's I think in the ailerons, 5945 on the elevator 5925 on the rudder and a mini servo on the throttle. It flew very nicely on the 1.60 and like I said if it had a pump then I am sure it would have been fine.
I sold the thing after it dead sticked
I have since been flying my 29% Ultimate for a bipe which will be replaced by the 38% Christen eagle.
I would do one again with the 1.60 or def. the Saito 220 for awesome expensive power! Just put a pump on it. It was surely a nice looking plane and I even bought a new cowl for it.