The original BME 58's had too thin of a back plate on the case which caused problems, that since has been fix from what I have been told.
To answer your question. I own that plane and have run a DA-50, G62-lite, and a BME 58 on it. I have run all on both stock mufflers and tuned pipes, three different tuned pipes on each to boot. So I have a little experience
I now only run the 58 in my yak. The plane flies best with this light 58 and has the most power. The only engine with more power was the g62 lite on a mac's open pipe, but the wing load was heavier than I cared for, didn't fly as nice.
I have about 25+ gallons through my 58, it has had the snot beaten out of it since day one. To date it has taken all the abuse and just keeps loving it. This is my favorite 50'cc class engine, but I have not tried the DL55 yet.