Dpn't worry, the reason the stuff you picked off early sucked because it was not dried or cured properly.

Theoretically your plants could be harvested now, But I would highly reccomend leaving it a little longer, some people/plants don't harvest untill around the day 80 mark, But I think yours will be ready sooner, hard to tell without close-up detailed pics.

Just relax! you've done a great job so far and you're almost there!
PLEEEAAASE take the time to cure nearly all the buds (I'm sure you'll be dying to try some a little sooner) and do a good job of it, untill they are thoroughly cured.

It really gets the best out of your smoke, After all the time and effort put in so far, I'm sure you want the most from your harvest!