Absolutely different parents living in a different part of the country (the greater New York/Tri-State area comes to mind). My mother battled a variety of health issues—asthma, Systemic Lupus Erythematosis and cancer, for starters—all of her life. My dad was even worse: as a high-functioning Asperger’s Syndrome adult, he was unable to cope with many areas of life, was hopeless when it came to managing his finances, was hyper religious to an extreme degree, and generally made life miserable for everyone around him.
Plus, replacing my mother would also get rid of her family, which included an uncle who was a violence-oriented bigot who hated Native Americans with a passion, hated my dad, and used threats of violence to coerce me into majoring in business (instead of science) in college. (His sole remark when I told him I was a chemistry major was “Chemistry? You can’t get a job (he pronounced it “jeb”) with a degree in chemistry.”)
With different parents, as has already been touched on in this thread, I would meet different people, visit different places, have different experiences, but I don’t see those differences as negatives. Yes, I would be different than I am now, but I see that as a good thing.