Eh there's overlooking flaws and then there's putting up with abuse/infidelity/incompatibility in life goals. My ex was pretty much a value meal of all three, and I loved him when I left him. It took me a couple years to stop loving him, but leaving him was one of the best things I did for myself. I wish I left him sooner, but what's done is done.
The love I felt for him was a lot different than the love my husband and I share. My ex and I were like friends who slept together. We never really had the intimacy (emotional, spiritual, life, not sexual) that I think you need in a relationship. There was always a wall. Don't get me wrong; I think friendship is a very important part of a relationship. It's just not the only element.
When someone says that they overlook flaws, I hope they mean personal habits, shortcomings, personality issues/minor flaws and not the biggies like contempt, abuse, cheating, or forcing the person to sacrifice personal dreams and goals.