Features that used to work but aren't now - biggest is for me is bill payment integration. Used to be when you reconciled an account you'd get a popup question if you'd like to schedule payment for the bill? And the bill would be entered on a pop-up. I no longer use Quicken for electronic payments because my credit rating was threatened by its error rates (multiple payments on some accounts, ignoring payments on others).
And making downloads work once and only once. I'm getting retroactive entries on downloads that are messing up account balances and reconciliations (e.g. balance as of beginning of statement.)
I could go on….