Ask HN: How do you use iTerm2? Its best features?

I recently started using iTerm2 on a mac, it seemed so cool. But I quickly got sick of it being so slow to startup, sometimes 10 or 20 seconds, and even sometimes slows/freezes the machine with a few windows open. Seems very bloated. So I stopped using it before I got to know its best features. (I had the daily tips appear daily, but never learnt anything from that.)

What are the things people use it for that good ol' Terminal bash can't do? The features that make it worth using. Thanks!