$180 is a good price if it is in nice shape. If it is SS, it is even better. I am looking for a Sevice Six to add to my Security and Speed Six colllection. If I was a nice one for $180, I would part with the cash without a second thought.
The Six Series are nice guns for the money and they are tough as nails but they are not quite as refined as S&W revolvers. They tend to have worse triggers and that lends to them being harder to shoot accuratly but I think the inherent accuracy is close to a S&W.
If you want a reliable, tough and trouble free revovler, the Six Series can't be beat. If you want a smooth and light SA trigger and a gun with accuracy enough to compeat in Bullseye matches, you want a S&W.