I built my own, I've since gone to a shop vac attached to the SawStop blade guard attachment.
Two things I've learned from this:
First, make sure that you've got a design that isn't very wide. I had a build like the one in the video, and found it was limited by the width, which would leave me no place to run the push block through. My current design is about 4 1/2" since I had a 4" port, and I was coping the SawStop/Excaliber floating arm guard. If I re-do it, I'll put the port on the side, not the top, and reduce the width to 1-2".
Second, make sure that you can get it out of the way easily. I've yet to see a design that doesn't get in the way with extremely narrow cuts, so you need to make it so that it can be pushed out of the way, or removed entirely. If it's not easy you'll get annoyed with it, and remove it sooner or later.
I found this design to be pretty good. In particular I like his guard, very cool.
https://www.youtube.com/watch?v=nhEZEnu9Gak