I accept Best Offers all the time, though the downside of the feature is having to look at the ridiculous offers some people submit.
Every now and then, I will block people from my items when they submit dumb offers that waste my time. In one case, I had a guy write me to ask why he couldn't bid on an item, I looked it up and sure enough it was because he sent me a $15 offer for a $150BV card I had listed (for $100). He didn't write me back.