I love them!
Once my bottles are sanitized, I put them in and they drain nicely, as I'm bottling. Once I've bottled and capped, I then rinse the outside of my filled bottles under warm tap water to get any stickiness removed and stack them in the racks and let them drip dry.
I have two of them. They don't take up as much space as a bottle tree. I didn't like the idea of a bottle tree, because you had to sanitize it, since the stem goes up inside of the bottle. Sanitizing a bottle tree didn't seem like it would be very easy.
With the racks, I just clean them and then dunk them down into a bucket of starsan water and their sanitized. Simple design. I don't have the tray that goes under it, but I don't need it. I have a rolling cart that I put a towel on and put my racks on top of that.