I was on the design team for the PS machines. (I say design team, I mean it was three people in a room for the whole thing [circuits/software/mechanical design].)
The main advantages of a high end machine are more accurate control (small advantage) and circulation (big advantage). The linked article's control algorithm is primitive (to say the least), and probably only marginally maintains set temp. The PS machines are accurate to < 0.01 degree (which for food doesn't matter), but the control software is the same between the food machines, and high end chemistry equipment.
As far as I can tell, some small waterproof fans would be more than enough for sufficient circulation. Why is that a specific advantage of high-end ones?
flow is very important with the temperature gradients that can exist in fluid. When you're talking about 0.01 and 0.001 degrees, flow is really important.
The main advantages of a high end machine are more accurate control (small advantage) and circulation (big advantage). The linked article's control algorithm is primitive (to say the least), and probably only marginally maintains set temp. The PS machines are accurate to < 0.01 degree (which for food doesn't matter), but the control software is the same between the food machines, and high end chemistry equipment.