Yes, it does reach 100%. After 1 full-powered vote, you'll drop to 98%.
I'd argue that having 100% voting power is a bad thing because it means you're letting voting power (influence) go to waste. On the contrary, if you never let your voting power reach 100%, you're not letting any of your influence disappear. I like to always have my voting power at 80% or below because that means I can go a full 24 hours without voting, and not concern myself about wasting voting power.