The problem with the 606f is it feathers and chews the back of the knobs under breaking on blacktop. It ends up with all your center knobbs sloping backwards. It soon turns into a very loud and vibrational tyre. The 907f with its row of split pairs around the center distributes the load under breaking better, takes longer to feather and is more dependable for a much longer time. A half worn 606f is scary in anything wet but a 3/4 worn 907f you can still depend on. You get more bang for your bucks in my opinion.
K60 was on my bike when I bought it. I swear it caused me to hiside when the front gripped and the rear slid out. I vote no confidence in those tyres. Probably great for long dirt road rides though.
Husqvarna TE610 Adv
Husqvarna WR 300 2T