Yeah, the de-essing technique here, whatever means it's done with, needs some adjusting. That high end of the vocal is close to lisping. It sounds very unnatural and overly processed. Every "s" sound features this.
I thought the guitars sounded pretty good. The toms are really, really lacking any character or attack at all. They are pretty dull/flat. It might be the way they were captured, if they are played live. Snare is rather dull as well/flat as well.
It's a good song, but the mix needs some work.