There is a big difference between knowing that the person you are marrying/married to is not perfect, and feeling that you “settled”.
“settling” implies (to me) that you feel you really are wishing for someone different or better. going into marriage with the attitude that your spouse is second-rate is a recipe for disaster.
Before you make a lifetime committment to another person you must be honest with yourself! Ask yourself, can I really accept this person as he/she is? will I always be wondering if I should have held out for better?