It's very quiet. There is a slight low pitched hum about it but I think it has something to do with the way the pump slips over the mounting bracket on the bottom. It's not the tightest fit, so that's the only thing I can think of that would cause it.
Not sure about the additional plugs for the drain. I'm not using mine at the moment - no real desire to. I'd rather remove the cup and clean the neck and cup to keep performance at it's peak. I think drain lines are for the lazy and since you get build-up in the neck, performance slows.
The pic of the drain line looks bad, but it comes pre-assembled on the cup with the valve and tubing, so I just wrapped the tubing around the skimmer body to keep it out of the way. It's not obtrusive or anything.
When I was taking the pics, I disconnected the silencer from the tubing and there was no difference in noise, but when I went to re-connect it I accidentally covered the air opening at the top of the silencer with my finger and there's a definite suction going on.
I don't think this is anywhere near broken in yet, but after less than 24 hrs later, it's pulling foam, has a nice head and is skimming very well IMO. I'd recommend it. I mean for $150 shipped, it's worth it IMO.
