Just to throw my hat in the ring here, I came from the same place as Kenny. I have had Kontakt/Komplete on my shopping list for years, but never pulled the trigger due to cost. Same for Omnisphere, too expensive.
I upgraded to Platinum this year, and wished to close some gaps in sound making plugins, without breaking the bank.
The deal for the AIR instrument collection is awesome. I don't think it's a replacement for Komplete, but it includes 10 great instruments, with a decent preset collection for each of them. If you are into sound design, you will have fun with them! I was only originally really interested in Hybrid, but when the package deal came around, it blew my mind!
I would keep the Komplete, and pick up AIR for cheap, then install and audition them all, then pick and choose what VSTs you want to install for keeps from both worlds ...
I just have to say, for the included keyboard VSTs, Mini-Grand is good grand piano, Velvet is a good digital piano (Rhodes and Wurli), and DB-33 is a good B-3 organ with a great Leslie cab sim, that comes with a separate FX only cab sim version.
The included synths, Hybrid, Vacuum Pro, and Loom, provide a good coverage of hybrid, virtual analog, and additive synthesis, with complete control over sound design parameters. The preset libraries by professional sound designers give excellent starting points to begin exploring.
The Strike virtual drummer is excellent with a 19GB library, as well as the Structure sampler. Even with the included large library, you can import your own samples into Structure. Wave editing and slicing, keyboard mapping, all included. Structure is multi-timbral and can add as many parts as your PC can hold. The downside is there is little to no 3rd party support for external libraries such as you find with Kontakt. But what you get with Structure is 37 GB of great samples to work with.
Then even the lowly $1 Xpand!2 synth is a rompler workstation with 2500 sounds, and is 4-part multi-timbral. This is a layering, or keyboard splitting monster with every sound known to mankind included.
Just saying...
And if that's not enough, just go pick up Synthmaster while it's still on sale. I did!


And since I already have the free Kontakt Player, if there is another sound that I need before I can spring for the full NI deal, I can just pick up a Kontakt Player friendly sound library. There seem to be many of those available now ...