What does LastPass do well? LastPass works and elegantly right from the start. I use their suggested passwords, which auto-fill on the 'type again' bit. The pop-ups and fill suggestions work like clockwork.
What does LastPass not do well? No issues at all that I'm aware of.
What do you wish you had known about LastPass before using? I wish that I was an early adopter and started to use it earlier. I had my little black book, scraps of paper and passwords as notes on my mobile phone. Like a fool, I had hundreds of passwords going back years and would keep entering the wrong one. I wish that I'd tried LastPass as soon as I heard about them.
Have you used a competitor to LastPass? If so, how does it compare? I've also used a higher level password protector vault, where I had to log in with passwords, packing keys, and so on. It was convoluted, and no longer necessary with modern improvements such as 2FA on my most essential logins.