I've used Mint for many years and will continue to as long as it's workable, but the real flaw with it is that companies can choose to cut off access to it at any time. I just recently ran into that a few weeks ago, with my main credit card cutting off access, and it was a huge pain - I had to get a new card quickly, switch over all our auto payments, add manual transactions for a bunch of stuff to Mint, and basically do a fair bit of messing around to fix it, because I didn't realize at first that it was permanent - I assumed it was just a temporary issue due to their new website. It certainly pissed me off, anyway. Now everything's operational again with the new card, but it was an annoying few weeks.
I haven't used YNAB because 1. I don't want to pay and 2. It goes against my philosophy of doing as little work as possible for financial things.