I have bought it. And love it. What exactly are you looking for? Well that's a good question!
Let me say right off, I have always loved my Addictive Drums - it does need an update without doubt now (especially things like the beats browser which is not good) but at least we have 64 bit compatibility and it still sounds great.
When Keys was first announced, I did think it was going to be in some way different to other Piano Libraries and because I like Addictive Drums I assumed it would be "cutting edge" sort of thing - but in the end it didn't appear that it was, so I didn't bother even downloading the small (free?) version.
However I do like the look of it - and I expect this is the main reason why I keep looking at it!
What I suppose I would really like to know is how does it differ / why is it better than other Piano Libraries etc.
I have a few Pianos / Electric Pianos in Kontakt and A superb Piano and EP in Mach five
Cheers
Nigel