I upgraded when they added the "extra step" for entering foods and that alone was worth it for me.
the entire thing is fairly seamless, it seems to be having a few minor issues over the last couple of weeks ( but i am sure they are on the regular accounts also)
I can enter an entire day in about 5 minutes or less.
And like you i have been using FD on and off for years but since i have paid, I have not missed inputting my foods in over 6 months no matter how bad i was that day.
If you pay for something you tend to use it.
which has kept me accountable and I have had the most success at my weight loss in years
I will be renewing my account when it comes up