I took the 851 for a 250 mile spin through Gallina (NM 96) last Saturday. No leaks, though I do need to wash off the bugs.
The verdict on the Conti cans: looks +7; sound -1 when compared to the de-baffled stock setup they replace. They may be an ounce or two lighter.
However, they still sound terrific and they look superb. The wrappers have a Termignoni logo on them, but the handwritten label says it all: Coppia scarichi 851 Corsa.