By "flakes," people mean flakes who say they'll come right over, but never actually show up.
Oh yeah. I just sold an old three speed for $50. I had a dozen responses in the first few hours but it took me TWO WEEKS to finally get someone who would actually show up. It turned out some were posting from other states with no ability to get the bike at all. Weird.
Also, ditto CASH MONEY ONLY and meet at a public neutral location if possible. I usually set up meetings for near my work at lunchtime or after work.
They are both willing to pay in standard US checks, which is better than a money order or something else.
Checks better than a MO? On what planet? A check is just a piece of paper. It has absolutely no inherent value and takes days to actually clear even if it is real (which you may find out about when the money you thought you had vanishes as the check comes up bogus). A US Postal Money order isn't quite cash money, but it's close. Much, much closer than any bank's check for sure.