I use it, and find it both amazing and terrifying (I could describe the whole EZ line that way). What exactly are you trying to do? I've used the built-in rhythmic chords and arpeggios, plus I've programmed the keyboard parts using either a DAW or Musescore if there was an exactly part that I wanted, and EZKeys gave me great results each time. I've yet to find anything that is easier to use. The sample quality seems pretty top-notch to me, but if you want to find higher quality samples they are out there at a higher quality price. If you do not currently have a DAW, I'd recommend getting Reaper (free) and try it out.
Also, what I find terrifying about EXKeys and especially EZBass is that the AI has gotten so good that it can create parts. I'm all about programming digital versions of instruments to play what you want, particularly in a studio setting. However, letting the digital instruments do the writing and creating seems, at least to me, like something else entirely. Still, the engineer in me is blown away by what these programs can do. It's the rapidly-becoming-irrelevant musician in me that is horrified.
Yeah. I love it. Not as much as EZBass, but I don’t play keyboards, but patching together midi files and using the circle of fifths wheel to follow your chord progression makes putting keyboard parts together pretty easy.