The first sous vide I attempted in college was using a thermo controller rigged to an on off switch for a dumb slow cooker. Things have come full circle. I did this in an hour or two, the logic isn't difficult. I'm sure it works well enough.
That's a good price and deal, except for the counter space it needs. Joule and Anova both cost only a little more and are more flexible in my opinion. Though this vessel like the SVS lends itself to a few recipes the stick models can't be used on.
I built my own and quickly went for a new Anova since it just seemed much safer than my frankenheater.