Since I seem to be their biggest champion around here, I'll help you out. I have a 1.48 in my DP Ultimate and it performs VERY well.... Engine can be hand started, has a nice slow reliable idle, smooth transition and excellent top end. I too, have the ASP108 carb as the stock MDS carb was not properly suited for the engine. They would run rich on the ground and too lean in the air, causing flame outs. Replacing the carb fixed that problem. Supposedly MDS had redesigned the carb now. I have not seen Horizon offer a carb exchange program yet tho.
I run mine on 10% Omega with a couple of extra ounces of castor for better lube.