Nobody is arguing that, the point is does it matter to get into med school? Not really. Why not? Because most schools don't give them. If your school decides to go with a 5.0 system it doesn't give you a better chance to get in just because other schools are on a 4.0 system. 4.3 is no different than that.
If this whole discussion is just about if an A+ is better than an A at schools that offer both, then the answer is obvious, just like an A is better than an A-, etc. If it is that an A+ will help you get into med school then the answer is far from obvious.
But I really don't care, go ahead an tell yourselves schools will drool over you for your A+ grades. Maybe some will, but most will just cut through the crap and see how your MCAT and GPA correspond.