So I've had my skimmer for a few weeks now and overall I'm very happy with it.
It's not quite as quiet as I had hoped. Several people had posted that it was virtually silent, and while it is definitely quiet, I wouldn't call it silent. I got a sound meter for my iPhone and it puts the sound level at 50-52 dB about a foot away from the skimmer. Compare that with 48-50dB for my Waveline DC 10000II pump and 60-65dB for my old Reef Octopus XS200 skimmer. The noise is a combination of a soft hum from the pump and a slight hiss from the air intake. Either way, it's a clear improvement over my last skimmer, and with the doors closed to the stand you can barely hear it, so it's quiet enough for me.
As others have commented, the construction is very good. It has a nice small footprint in the sump and definitely saves space over my last skimmer. (I attached a picture of it next to my old Reef Octopus skimmer below for comparison.) The skimmer cup has a silicone o-ring that gives a nice tight fit into the neck ring on the body. This is personal preference, but I prefer this to the screw-on attachment of the Vertex; if you have a hose draining the cup to a separate waste container, simply lifting off the cup is a lot easer than unscrewing it. It comes with a ½"(?) John Guest elbow attached for external collection as well as a piece of silicone tubing should you wish to use a separate collection container.
I ran it for 24 hrs in some vinegar water and then put it in my sump. The instructions say to wait a couple weeks before adjusting it, but it started making skimmate almost immediately for me. Currently it's making about a cup and a half of dark-tea colored skimmate a day. I haven't tried adjusting it to get thicker skimmate; perhaps someone else can comment on that. I've also found it to be much more consistent than my last skimmer. My old skimmer was rather touchy and would go out of adjustment pretty easily. This one has been rock solid.
It uses a Sicce PSK 600 that draws about 40W of power. It has a stock impeller, so replacement parts should be reasonably easy to get.
One of the things I wanted to do was to attach a float switch to the lid. There's about ⅞" between the outer wall of the cup and the deflector ring on the lid, so it's still too narrow to attach a regular float switch (~1" diameter float.) I haven't looked to see if I can find a smaller float, but I'll probably just use an external container anyway.
Overall, I'm very impressed with it and would definitely recommend it.