I have a DA 50 and for 3D I like a 22 x 8 better than anything else. I've flown 23 x 8 Mej, 24 x 8 Menz and 23 x 8 NX and the engine simply will not rpm in the range where it makes best power for 3D. With these larger props the thrust is huge but the throttle response is lacking and the rpms are below where the DA really shines, over 7K is where the best performance is obtained with the DA 50 IMO. 3D flying is all about quick throttle response and big thrust changes, loose either one of those and your going to get low and regret it.

IME wing rocking is never about a single, simple thing it's always a combination of small things all working against you at the same time.