Yeah, I was a little leary, but for $50, they better work. It did hold water during an early test. The idea behind it is that you get absolutely no sediment in your bottled/kegged beer. Because of the conical shape, your loss from those bottom 2 or 3 inches is quite minimal. Certainly you could rack from the bottom, but you'd probably lose the same amount by waiting for the sediment to clear. Also, the dump valve on my design is much larger at 1", and the racking port is only 1/2," so you'll get finer flow control.
I've seen pics of the Pastor's setup, and I've also personally used a sleeved fermenter when sitting in on someeone else's brew. I'd sleeve the fermenters, but that would immediately take them out of the price range I'm shooting for (cheaper than the Fermenator), and it would require a lot more time with a lot more risk incurred by doing that much leak-proof welding. Glycol in a small chest freezer works really well, either through a sleeve or a coil, but I doubt it's very much cheaper than the electronic stuff. Either way, you're gonna need a temperature controller, and you'll need a pump for the glycol setup. I'm just going to build a fermentation closet on the back porch that includes a small window A/C unit, a heating element (of undetermined type right now), and a Ranco temperature controller. I'll post pics of that in another thread when I start building it.