Quick review based on first use. I have a Northern Brewer Rye PA fermenting in a better bottle inside the Cool Brewing fermenting cooler. The cooler is considerably wider than I expected, which is okay because it allows for me to put a one gallon milk jug for my blowoff container and two 1-liter frozen water bottles in there as well and still have plenty of room. Probably could fit 2-3 more frozen water bottles. I like that the thing is soft sided as it will be easy to pack away in the closet, but it's a little annoying in that the sides kind of collapse if it's not completely full of things. Not a huge deal, just looks odd.
Performance wise, during primary fermentation with US-05, using 2 frozen 1-liter bottles (offset from each other 12 hrs though if that makes sense), it kept it at 64-66 deg with an ambient temp of 70 deg. Now that primary fermentation has slowed it appears to be keeping it at 60-62 deg with an ambient temp of 70 deg still. Will be interesting to see the difference on a beer with a crazy fermentation like a tripel with 3787 that I did.