I have ridden all Sectors from all years and the K-Free. As much do to the fin shape as the three fin setup, the K-Free feels like a Sector 54 but planes as early and fast as a Sector 60. Yes, the K-Free likes to be ridden flat, but it can also use some rail like a smaller board in waves. The only thing I really wanted out of the K-Free was a two strap option so I could compare it directly to the Sector 54 in the same setup.
We used to sell both, but now only the RRD, so like, whatevuh dude.