I think you’re dealing with miniscule differences overall between each machine. It can be hard to discern who is just parroting something they heard from Lance vs things that are objective facts. If you’re chasing perfection I’d be looking at something more expensive. But there’s also your beans which is an easier thing to account for. How fresh are they, what kind of varietals are you choosing. Try different origins and see how the tastes change. I think that would get you much further than worrying about which grinder to upgrade to.
Ie if you don’t already have practiced tastes it might be better to focus on that before anything else. It’ll help you experiment with something more fun like different flavors rather than eeking more or better flavor from your existing stock.