I'd give them both an "A+" as parents. That's not because they didn't make a few mistakes here or there. All parents make mistakes, and sometimes it's more a matter of their not understanding what an individual child wants/needs than it is the parents' failing as parents. BUT, they were, amazingly good parents, and they're the reason I was a solid and secure little kid who was understanding enough, and reasonable enough, to realize that when they did occasionally mess up it was because they didn't really know better.
They were hard-working, caring, generous people who managed to make sure we had pretty much everything (minus some luxuries), that the house was peaceful and happy. They were the reason I knew that children could be raised to be well behaved and respectful without being yelled at or hit. They were examples of working together, helping other people when they needed it, taking care of extended family when they needed some help. They were also examples of "figuring out a way" and "pulling together" when there were challenges. They were also the reason I grew up knowing how to make babies and young children feel very safe and secure and happy, and respecting that babies and children are separate little individuals.
They were a little too much when it came to thinking that every little thing I did wrong was a sign of any problem more serious than my just doing what all kids do, which was "something stupid". They could have also done a little better when it came to my developing confidence in dealing with world (different from self-esteem, which I have). In fact, they worried so much about making sure I "never got a big head" they kind of created some confidence problems for me. For me, confidence wasn't just "bestowed" on me. On the other hand, I have a nicely balanced ego that lets me truly feel and know that I'm no better and no less than anyone else (and I'm not talking about individual skills; I mean "being respect-worthy" or "value-worthy" as a person).
And, while I have no doubt my own three children would have a complaint or two about something I did; my parents are the reason I was able to raise the children I have, and the reason I at least did well enough that they have, from time to time, let me know that they approve of a lot of the things I've done/been as a parent. They were exceptional,(even if not perfect) and I'm incredibly thankful to have been so very fortunate enough to have had them in my life.