The reason its is K5 specific is it dose not need a full version of Kontakt. As a Kontakt (4) owner it would have been better for me if it did require the full version of Kontakt. But it makes it useable for non Kontakt owners.
I can understand NI only licencing
new products for the latest player. I do find it annoying that they have made all Native Instruments old products K5 only however.
So the player is free, whats the problem? Well what sucks is K5 is offically Windows 7 only. It runs fine on my Vista PC and happily coexists with the full Kontakt 4 -
BUT! I am reluctant to spend money on products that are not supported on my DAW
On the potential upside, for a non Kontakt owner there is a possibility that NI will run a cross grade offer where this product will entitle you to a discount on the full version of Kontakt. I got a big discount a while back because I had bought Steven Slate drums in a No Brainer.