I love NI's software, and I bought Kore and Komplete last year (about a month before K5 was announced to be released
). The only criticism I have with the whole package is that the Kore hardware is not a crucial necessity. While it's fantastic to have this lovely, futuristic-looking box, it
is little more than a software-specific controller/transport; especially now they have removed the built-in audio interface for the version 2 model.
Having said that, the integration is superb, and the resolution on each rotary controller is so high. Plus it has the ability to create control maps for your 3rd party plugins; DX, VSTi or
AU. But I'll tell you what I've found which makes it all the more fantastic; if you're a Pro Tools user, you can use the Kore multi-out RTAS plugin and load all your non-RTAS (i.e. plugins you cannot get for PT) plugins into separate channels, and route them with aux outs, midi ins, etc! To me, that is a stunning bonus!
The Komplete package itself is great. You can't go wrong with Native Instruments plugins. They're so innovative, and will provide years of fun.
You really can't go wrong for the price! But once you've checked it out properly, go on to the NI forum and get everyone to look at my post about 'Kore Mode'; it's a brilliant idea! I don't know why no one's responded to my post.
Check it out here 
I hope I've helped!