The first thing I have to say about the folding proofer ($148) from Brod & Taylor is, "How have I survived so long without this?"
Okay, I'm in the midst of developing bread recipes for a cookbook, so I'm baking more bread than a normal person. But even when I'm back to my normal rate of bread production, this will be a handy thing to have. And when it's not in use, it folds for more compact storage. That's always a bonus.
When I first unpacked the proofer, I thought it might be a little too small—it looked like it might be too short to fit my stand mixer bowl. But, no, the bowl fit in the proofer, with a little headroom. The interior measures 12 1/2 x 15 inches, and about 8 1/5 high, so it's too small for a half-sheet pan, but it's fine for plenty of other pans and bowls.
This heats to a range of 70 to 120°F in one-degree increments, so besides proofing dough you can use it for fermenting yogurt or similar products. I been using it pretty constantly for proofing dough, and I've made several batches of yogurt as well. I suspect it would also be useful for keeping food warm if you're cooking in batches or if something is finished a little sooner than it should be, but I haven't tried using it for that purpose.
Before I had this proofer to work with, my favorite place to proof dough was in my oven with the light on. But that's no use when I need the oven for something else, which is usually the case.
If you don't bake a lot of bread, obviously you won't need this. But if you make a lot of bread and you want consistent temperature for rising, this just might come in handy.
Disclaimer: Testing samples were provided to Serious Eats.