To go a little further, I’d rank the hubs:
1. Otter – Seems to be the most durable and has the best bag and fit on the market. They’re warm and super easy to set-up or take down. They have tons of useful pockets. The only cons I’ve seen in various models is window placement being a bit high. They don’t really have lower end models to compare apples to apples with some other brands though. All their stuff is top of the line.
2. Eskimo – The newer Eskimo stuff could probably be ranked 1A as they are awfully similar to Otter. Their bags aren’t maybe quite as durable or spacious for packing. There are some well-known complaints about their fabric stitching maybe not being quite what Otters is. They were the first to market with the easy walk through door. Now that others have picked that feature up their advantage will be lost.
3. Clam – Clam has a wide range of hubs. Their cheaper older stuff was notorious for the poles breaking and the connecters where the poles meet cracking in the cold with use. If you buy some of their top of the line models the durability and quality is better. I was in one of the Jason Mitchel x5000 shacks a few weeks ago and it was nice. These models are only a fraction of what they sell though.
4. Frabill – I’ve admittedly only been in 1 Frabill hub recently. It doesn’t seem like they’re marketed well or as widely produced. The insulated fabric had a substantially different feel than the competitors…somewhat stiffer. This isn’t really a fair review, but I’d still give the other 3 a long look before Frabill.