I've been using YNAB since October 2012, and I can honestly say it has been a key part of my success lately.
I did use Mint.com a year or so ago, I really didn't like it.
Like others have said, YNAB really is a change of mindset... Use the money you have now, and decide what it needs to do. If you want 50% to investments, budget 50% to your investments and then allocate the rest to your bills.
It has the ability to be as general, or as granular as you want... You can have 4 or 40 categories, it's up to you. I laugh when people scoff at the $60 price tag, citing some other free way of doing it... It's not $60 per month, it's $60 one time, an *investment* in budgeting. Plus, it's only $54 if you use a referral link (I bought the domain www.youneedynab.com
as my referral code ). I've spent $60 on a few different computer games over the past few years, and I felt that spending $60 on a program to help me saving and spending wisely was a great investment.
I literally went from being ignorant and always having no money left to invest (or pay off debt in my case), to putting nearly $1000 per month (20% of income) towards debt repayment.. I attribute quite a bit of this to the manual entry of spending, when I or my wife spends money on something, I know when we get home I am going to enter that into YNAB, and I better have enough $ in the category it belongs to! Before I would have merely checked how much $ was in my account, thinking in my head "Ok, rent is due on the 1st, car insurance on the 4th, Cable bill is due sometime soon" forgetting about many many bills that would come out on the 1st (home insurance, bank fees, wife's student loan payment, etc etc...
The "budget in my head" failed me for so many years... I needed something better.
Thinking of it now, if I had YNAB 5 years ago, I would be debt free, and saving 25+% of my income.
If I started YNAB 5 years from now, I'd probably be exactly where I am now.
Then again, YNAB or any other budgeting process will only do so much, the power comes from implementing
the budget. Nothing will help if you ignore it...
Having said that, I fully understand that a lot of people are naturally frugal, or naturally able to budget, once you hit your savings goal, the rest is free to spend. I am both impressed and respectful of that, more power to you if you can. One day I will likely be there too, and not need YNAB... But I'm still in the training phase :)
What I have to say about Mint vs YNAB:
Mint looks backwards and tells you what you had.
YNAB looks forwards, and tells you what you have.