I am a SMBC. My child is 9, and so far, so good. It was a great decision for me. My child has a pretty decent life on paper , and seems to be in good spirits.
I think my life is simpler in some ways than that of a married parent, as I don't have to discuss anything with anyone. It's harder, because there is no backup.
I will say that, as with a lot of things, it is easier with more money. I don't have family in the area. Being able to afford an emergency babysitting service, takeout or a cab when your schedule is tight, grocery delivery etc. really makes things easier. That's on top of daycare, camp, activities etc. The first few years are probably the hardest logistically.