I have one. It's nice. I don't know if it's "$24 nice," but it's essential if you're going to cook in a large vessel like the "classic" industry standard Cambro that everyone uses with Polyscience units. I'd agree with the Amazon review in that Big Clamp does sort of feel like an accessory that should just come with the circulator when you buy it.
The Big Clamp was always a planned feature, as the "interchangeable clips" system was one of Joule's selling points. But the rollout of Big Clamp had some missteps. They must have run into some problems getting it produced because it took (what felt like) forever for it to finally come to market. They first teased the prototype of the clamp in their "Game of Thrones feast" YouTube video, where they use Joule to cook a suckling pig in a Yeti cooler. (I prefer Pelican coolers, but whatever.) That video came out months before Joule even shipped, so I had the expectation that the clip would be available pretty much when Joule was available. Nope.
The nice thing about Joule as it comes from the factory is that you can cook in small vessels and not have to use a big old hot tub like you did with the old circulators. The downside was that there is no good way to use Joule with the kinds of containers traditionally used to cook sous vide (biggish Cambros and Lexans), much less large coolers for your sous vide suckling pig needs. I had my Joule for six months before the Big Clamp finally made it to market, and the lack of Big Clamp drove me nuts. My ultimate workaround was to take a can of beans, remove the paper label, stick Joule to the can with the magnet, and then use that as an anchor in the Cambro. I was pretty pissed off about the situation. When The Big Clamp became available, I placed my order literally within seconds of the announcement. I think they sold out the first batch in record time, if memory serves. Probably because everyone had been waiting half a year to use their Joule in a big Cambro without having a freaking can of beans stuck to it.
Anyway, you asked about Big Clamp, not The Rollout of Big Clamp. And the good news about the actual clamp is that it has a high build quality and the sort of excellent design you'd expect from the people who brought us Joule. Using the clamp with large containers is super easy -- it's easily the best "circulator attachment device" I've seen. It's light years beyond the agonizing "screw it on" clamps found on many popular brands. It does make Joule take up more space in a drawer if you leave the clamp on all the time, but it's so easy to swap them in and out that this is almost a non-concern. I paid $19 for it, and would gladly do so again. I might even pay $24. In part, that's because the clip is well constructed. In part, it's because the alternative is a can of beans.
