All good points, and yes I should have probably discerned the original question better before making my initial post about CGC 
. The thing is, I always collected PSA or BGS and I only have a small amount of CGC slabs overall. Back when they first got going, it seemed that their standard was very similar to BGS (i.e. actually difficult to score 10s, sub-grades, etc).
But then when they made all the old label 9.5s into “10s” that is where things sort of went stupid to me. Luckily for me I had a few 9.5s in my collection that I could ‘upgrade’ into 10s if I want to… but it’s sort of silly right? It just made it sort of confusing because they have 10 “Gem Mint” and 10 “Pristine”. I really feel this was a big mistake by CGC, but yet it seemed that the market was still paying a bit more for CGC 10 Gem over BGS 9.5 Gem, at least initially.
Anyway, yes I do think that BGS 10 Pristine should carry a premium over CGC 10 Gem Mint, given how rare they are and the fact it was always a very difficult grade to get on a lot of cards. If I had to choose, I would say I would go for BGS 10 over CGC 10 as well, I just rarely ever see them unfortunately.