OEM 1299 seat is the same as the OEM 899 (approximately 5mm taller than OEM 1199's) seat. Yes, it fits the 1199 and in my opinion, it is a good medium between the OEM 1199 seat and the DP comfort seat.
FYI
-OEM 1199 is rock hard but it sits you 'in the bike'.
-DP comfort seat is considerably softer/spongier but it sits you 'on the bike'.
-OEM 899/1299 seat is a middle ground between the two.
...The combination of the 1299's rake/geometry, seat, front fairing stay and taller windscreen are what lead you to feel that the bike is generally more comfortable than the 1199. That, as well as the 1299's less aggressive/twitchy throttle mapping (newer bike has a 'medium' throttle mode which the older bike doesn't have) make you feel the 1299 is more 'friendly'.
The 1199 and 1299 clip-ons are the same/interchangeable.