What is difference between NI 360 Pro and Komplete 15 Collector’s Edition?
Here are links to the lists of content :
Which Products Are Included with NI 360 Essentials / Plus / Pro?
Komplete 15 Collector’s Edition bundle compare
Apart from that then as far as I know then NI 360 is rent and K15CE is buy to own.
360 is a subscription plan available monthly or annually.
Komplete 15 Collector's Edition is a one-time purchase. With it, you'll get perpetual licenses for all the products right away.
Here is the detailed difference I found for instruments, but some mistakes may happen, especially that products availability is supposed to change on 360.Instruments Exclusive to Komplete 15 Collector's Edition (not in 360 Pro):
Even if it needs to be verified, it was very helpful for me so I hope it is for you.