Been using YNAB for over 7 years. Started on the old version and made the switch to the new version about 12 months after the changed.
It's been great. The methodology is my favorite bit. As you pointed out, it forces me to plan my spending. As for "off the cuff" spending, I have a "fun money" category that I use for impulse buys that I fund each month and let it grow for months if there's nothing I want.
I don't use the bank import, I just check my expenses against my bank account once a week and verify the numbers match up.
Overall, I am a big fan. They do it better than just about anyone, they have brought a lot of folks out of debt, their methodology is solid, and they are extremely customizable. I probably could pivot to my own spreadsheet or a free alternative, but having the phone app makes everything much easier for my wife and, honestly, I like the company and want to continue supporting them.