Well, to make a long story shorter (I hope) Keep in mind the ones I bought were probably 8 years ago so they might have fixed the plastic mold quality and seals but I doubt it.
I bought the first one (about 14 gallon size) and made a fermenter out of it, then bought two more for grain storage. I found that all of these had such inconsistent molding of the main vessel that I had to hand file it to make the gasket surfaces seal on the lid mount ring. After that I found that for the o-ring in the spin-on lid to seal it had to be screwed on so tight that it took a mallet to loosen it. Kind of impractical for something advertised as being better than regular bucket lids and costing $45+ each. I really didn’t care that the airlock didn’t bubble as I knew the nasties would not be able to just float in due to the poor seal, but with our high humidity here in Florida I wasn’t willing to leave my bulk grain possibly exposed to moisture and possibly insects (no rodents 
I just want to make sure people don’t think they are getting something better than buckets, and spending money for no reason. They should call them the “gimmick-Seal lids” not Gamma Seal. Just my experience, opinion, and a bit of humor.
Not to mention that if you need to really clean them you need to remove the lid mount and that is difficult and can break that part. If used for fermenters this is where the nasties hide. My solution and modification suggestions for this are at the bottom of the main page of my website. Pics of the vessels as fermenters is also on the site.