Akrapovic > DP Termignoni (with upmap)... better fit, finish, sound-- to my ears at least - and power curve.
Akrapovic > Carbon Termignoni (without upmap)... because I'm bias (and because my previous 1198's carbon termis yellowed in no more than 6 months; I'm left a little bitter).
In my opinion, youtube videos and/or listening to any Panigale exhaust while 'off' the bike simply don't do them justice because of where the exhausts are located. However, riding two 1199's (one equipt with Akrapovic and the other with DP stainless steel Termis) properly puts things into perspective. It is then that you (or I, in this case) realise that the two exhausts sound considerably different and the Akrapovic system is worlds apart.
Admittedly, the new carbon Termignoni has come a Long way. If you're as fond of carbon as I am, it certainly looks the part. With the new front-exit design, it definitely sounds the part too. And if you believe in the magic that is Rapid Bike like I do, then the fact that both, the Akrapovic, and the new carbon Termignoni come without a factory upmap... won't bother you at all.
Can't go wrong really.. Take your pick.