I hear the stories of differences quite often, but other than opinion, I have never seen any substantial proof that borg stuff is substantially different.
I see vinyl siding as .040 thick at borg and at a siding supplier at .044 That is a difference of .004 - the thickness of writing paper, or about the thickness of a human hair. That is not substantial.
As to cameras - a Camera with a model number at Walmart is going to be the same camera with the same model number at a camera store, but less money. I am NOT a camera "buff", but I have never had a problem with a walmart camera - canon, Nikon, Olympus or whatever brand name. On the other hand, IF, I were a camera buff and I wanted an expensive Digital SLR with special lenses and plan on spending $2500, I would not shop at walmart. I would want support from someone that knows what they are talking about.
I also think Best Buy is a LITTLE better than Walmart, but the staff is often a LITTLE knowledgeable, but be careful as they will impart opinion with the LITTLE knowledge.
Wally is fine on the low end, like the stuff I buy.
High end, I would recommend a good camera store.
But that is just MY opinion.