The second generation C-14 brake pads are more durable, make far less brake dust and give up some braking ability, especially initial bite, to the first gen. OEM pads. They are interchangeable on all model C-14's but the 2nd gen. pads are actually cheaper. I have used Gen. 1, Gen. 2 Kawasaki OEM pads, as well as EBC's and prefer the Kawasaki Gen. 2 overall. Plus the OEM pads have that really slick little pad life indicator groove in them- very handy when doing a quick check on the pad life.
Brian
Edited to add: Neither version of the OEM Kawasaki pads makes any noticeable noise and both are much quieter than EBC.
I replaced my original KAWI pads at 16k (front) and 19K (rear) with EBC HH sintered, They seem to wear a bit better as I am at 36K and the fronts are just about ready to go. Is there a brand of pads that have the wear properties of EBC without the WHISHHHHH sound upon use? Galfer maybe? Any ideas? I may try the Kawasaki (Newer) pads as I've heard they are a bit more durable.