I tested both k12 and k13, compared to gen1 low speed cornering is a bit harder at first, med and high are effortless and gives you more confidence.
One of my riding buddies has a k12s and we both use bridgestone s20 so the tires are the same.
Brakes on the K are amazing, assisted+abs.. this would be my no1 reason to change the fizzy for a K
He uses less fuel then my fz1..in the exact same riding conditions
bmw side-cases look good on the bike, perfect for a week ride
compared to modded gen1 , k is not much faster
now the min
-gearbox clunks
-suspension is only for very good roads
-low rpm power is ... not there
-maintenance costs
Now for the cost... fizzy offers more bike for less money, I'm waiting for a gen3, if that doesn't happen in 2014 I will consider a K-bike