I'm no electrical expert -- so I'm happy to pay Steven or Dave a profit. I know folks who are electrical experts -- or who have some experience with building stuff like this -- will say it's a simple build. That may be, but (a) it's not something I want to do and (b) the turnkey approach appeals to me.
BTW -- the other difference between Steven's systems and Dave's system is that Dave uses a Chugger pump. Steven uses a smaller (and, I'd suspect, just as effective) pump. A Chugger or a March is probably overkill for either system, and as I'm using Dave's system right now (literally, as I type this) I've toyed with the idea of going to the smaller pump.
I don't have the chugger mounted on wood -- and that's probably what I need to do -- but I have it sitting on top of an upturned bucket about 18 inches down from the kettle out. Chugger in is pointing down, Chugger out pointing up. I found I had to do this to get a decent enough drop to prevent air getting in the lines when I first start it. I thought about putting in a bleeder valve -- but I didn't want to mess around with taking everything apart, installing the second ball lock, and then Teflon-taping everything back up (lazy, I know).
Anyway, my thought -- and I might not be correct here -- is that the smaller pump might be something I could just put on the counter (as Steven does in the photos of the system and in the videos).
Finally, what I do like about the HG system -- and this goes for what I've seen of Steven's system, too -- is that it's really simple. Easy to set up, easy to take down and clean. My days of 10 gallon, 3 kettle HERMS in the backyard were fun -- but exhausting. The indoors BIAB is great -- and everything stows away nicely in the kettle after the brew.