Right now, I'm removing/replacing flagstone over concrete. Taking up the old, crumbly rock with a jack hammer was brutal. Cleaning the old mortar from the concrete was endless. Picking up the new stone and laying it, laborious and tedious. Now, the top step (pictured) took about 100# of grout and about 4 hours of stoop labor. My back and inner thighs are screaming!
But I'd rather spend a month of Sundays doing my front steps than deal with anything plumbing related. I HATE plumbing.