After having owned 4 Ducati's over the past 5 years, I am planning on getting an 1199 but for at least 1 year I wont buy any aftermarket exhaust. I want to see how this whole USB remap thing works out for them first. But besides that, I am SURE that this bike is going to have issues and bugs to work out as it is a complete clean sheet design. On my 1198 I never changed the exhaust, left it stock, and interestingly I never had any issues with the motor not running right, or having flat spots in the powerband, or any stalling issues at all.
With the 1199 I also think that there is less of a reason to change exhausts than with the underseat design bikes like the 1198. On those bikes the exhaust is a major design feature whose looks impact the bike to a large degree.. You can't really see much of the exhaust on the 1199, and to me the Termi's dont look different enough from the stock exhaust to be worth the ridiculous prices they ask for an inferior product. Yes, I believe Termignoni exhausts are inferior products compared to say, Akrapovic or Leo Vince, and I think most people would agree. For a while at least, I will be happy with the stock exhaust, the money I would spend on it would be better spent on track days and tires.