I wanted a Big Frig because of the pressure relief plug located higher on the side. Being able to release pressure to open the lid without spilling water out of the drain plug was a major selling point for me.
The 45 went on sale a cpl weeks ago & I ordered one. I was not disappointed, it is well insulated and IMO superior in quality to the other big names I own(Yeti & Rtic). The handles are far nicer and look to be more durable, the latches lock into place better as well. The day after the 45 showed up, I ordered a 2nd and used them both this past weekend. I will be ordering the smaller size next time I see it on sale as well.