I bought this several years back and still use it regularily.
I'm not a pro musician but more a hobby guy trying to learn piano and playing around with sounds. The Keys Duo is a nice product for combining different Piano libs from XLN. I chose the Grand Piano and the Modern Upright.
The UI and everything is great, the sounds are perfect and the options for different mics, mixes and effects are also great.
If I had to I'd def. buy it again.