Speaking from the very recent experience of buying a second hand HQ 16 via my local online classifieds, I would buy this way again. I have also given away quite a bit of stuff via my local Freecycle and it was always having someone come to my house.
When I went to see the HQ I was on my own, but the seller's husband was home for the first bit, then he left to run errands. I was in her home for at least one hour and had brought $500 cash to use as a deposit.
So from a buyers perspective, I was going to a strangers home with a considerable (for me) amount of cash in my purse. I paid the deposit, then returned the next day with the balance in cash. Together the three of us loaded the machine into my car.
But I live in a safe area where thefts and scams of buyers and sellers for online goods is very rare. I would buy and sell through local online classifieds again and would not hesitate to go to someone's home or have them come to mine. One couple delivered a sewing table I bought when they realized I did not have a truck and was going to have to rent one. It turned out their daughter's dance class was 1/2 mile from my home.
I am not sure that I would use Craigslist to sell, I like that the local online classified is less likely to get negative attention. I have bought via Craiglist in the past.