Kaiba is totally different from SZS, Kaiba is dystopian sci-fi. Watch the first two episodes of Kaiba so you can get a feel for the show.
The music is fantastic in Kaiba, especially the lyrics and keyboards in the ED, it couldn't be more perfect and I can't wait for a full version. It's calming, but gives you a feeling of melancholy at the same time. Very suitable for the series, I'm looking forward to the full versions.