Really? A spiders reaction to caffeine is your reason? I just quit caffeine. I'm ready for some conformation bias to justify my decision, but this is pretty weak.
No jitters but if I take all 4 at once I get a pretty unpleasant "coming up" feeling for about 15 minutes. I usually just have 2 a day, and I'd recommend people start with 1 just in the morning.
From persona experience i either have to go a few days without or drink my third cup (drip brewed) of the day to get anything noticeable.