I have the previous NIKs because they were giving them away for free at one time. Apart from trying them out when I first installed them, I have never used them again.
I find it far easier (and a great deal faster!) to use the standard editing tools to control exactly the affect that I am seeking instead of trying a splatter-shot roaming through all available plug-ins in the hope that one of them will deliver the result which I already have in mind.
When I first got involved in digital editing (some ten years before I used a digital camera), I bought all sorts of exciting sounding plug-ins.
Now I don't buy any of them, and very very rarely re-visit some of the more specialised ones which I once bought and which still run in today's OS.