5 years ago in a good market, I listed on Boat-US and Spinsheet, both online and in print. Only received one soft query. We eventually took the boat to a broker's and listed it in November. We had several interested people on the boat during the first week but then it got cold and the boat sold 3 months later in February (very cold de-winterizng the boat for seat trials!!).
We feel that the combination of having the boat at the broker's yard with the greater foot traffic resulted in a quick sale. The boat was in great shape and we did not give it away, so a ridiculously cheap price was not the factor in the quick sale. After survey & sea trial there were no price adjustments.
IMO, I'd use a broker again to sell a boat. I'd also use one to buy a boat, but that's another story. If you don't care how long it takes to sell or can't afford the broker's commission, then sell it yourself. Admittedly, there is a wide range of opinions on this topic, this is mine. Good and bad stories abound on the broker topic. If you find a reputable broker, then the commission is worth it, IMHO. Ours saved us 11.5% on the purchase of Victoria.