Having spent 4 training sessions with my IM trainer, I already can feel a slight improvement in the way that I play. I understand my openings a bit better, and my evaluation of middle game positions are more sound. Granted, I may not have the time (I'm still waiting for my first child to be born!) to pour over chess theory but at least I'm heading in the right direction. A look at my rating average also confirms my suspicion.
I am still susceptible to the occasional tactical/positional blunder (who isn't) but with daily use of the tactics trainer hopefully I shall make less mistakes.
So far so good. =)