I work in IT, and just like any other IT person, I can totally get into automation/gadgets. Despite this, I have absolutely no intention of buying a controller. Why you ask? Prepare for hot take:
HAVE YOU SEEN THE PRICES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! EVEN MARTIN SHKRELI IS JEALOUS OF THAT LEVEL OF PRICE GOUGING!!!!!!!!!
I apologize for that, but I really needed to get that off my chest. Seriously though, you are looking at $100 (If that, IMO I bet it's more like $50) for the actual cost of the hardware. There's nothing even close to "high tech" about it, the technology used is at least 20 years old. What about the software you say? I bet any college student off craig's list doing part time software development could take care of it. Now that we have covered hardware and software, you guessed it, on to probes. The problem with the probes is that, to it bluntly, it's completely wrong. As you go up the product line, you simply get a better probe. That's just dumb, really dumb. A slight increase in the % accuracy of a probe has saved someone's tank absolutely never. You know what can kill a tank though real quick? The inevitable probe failure (aka to engineers, MTBF, Mean Time Before Failue). Instead of getting a better probe in the higher end models, you should just get more probes for redundancy. With only one probe, you wouldn't know it went bad till it was too late. With 2 probes, you would know that one is off, but unfortunately you don't know which. Must have 3, when the controller sees the discrepancy between probes, it simply ignores the weird one and alerts you to possible probe failure.
Basically, my issue is that the cost to features/capabilities ratio makes absolutely no sense! Not to mention I think they give you a false sense of security due to the critical points of failure I can see with the setup. You only have the illusion of control, why? Given enough time, Murphy's law always wins.
Enough ranting, because credit should be given where credit is due. The temp monitoring and auto-heater shut-off appears solid. I doubt I could improve on that design. With a $700 budget though, I know I could make something with so many more features (To clarify, by features I mean utility based items. The lightning storm my LED's can do is not a feature, that's a gimmick) that it would blow the apex out of the water (Pun intended

). For example, I could integrate a webcam for live viewing relatively easy and for less than $30 using
this. Just matching features though, I don't know how much cheaper I could DIY one. Tough to beat the economies of scale a company has when buying in bulk.
I can't be the only one with these thoughts... I'm sure someone else has explored this route as well, so if you have any good links, toss them my way. I would like to help the cause!