Yes, the best scenario of the first case is better than the worst scenario of the second case, but personally i'm more interested on the best scenario of both c

Yes, the best scenario of the first case is better than the worst scenario of the second case, but personally i'm more interested on the best scenario of both cases - especially since we already have working OpenGL implementations that take advantage of how OpenGL is specified. I'd rather see a push to improve subpar implementations so they reach parity with the good implementations than throw all implementations out of the window because of the bad ones.