Very cool song.

Yep, it's amazing how far the technology has come in the last year or two.

One of the things that I found uncomfortable to my ear was the phrasing of certain words. Accents in the wrong places etc... That makes this sound a bit robotic and unnatural in a few places.

Working with synth voices requires attention to the details. I have spent quite a bit of time editing several of my synth voice creations to get the phrasing to sound "natural". It's not always easy but it's worth the effort involved. Just remember that you're essentially working with midi and that will default to, in most cases, a very boring and precise rendering, whether it's an instrument or a synth voice. Work on the details and you'll see a huge step up in realism.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.