Other features of better drives are the ability to run at higher voltage. The 542 is about 50V, tb6600 is 42V I believe, whereas the other drives you mention in post 1 are rated at 80V. This means more stepper torque and ability to run at a higher speed. So a much faster machine.

Also, and sort of related is the tendency to miss steps on the cheaper drivers because you are trying to get the most out of them. By way of example I had an all-in-one board (system3?) which was rated at 24V to 30V. I was advised by the supplier that it could be ran it 32V to squeeze more performance out. I had lots of missed steps and it took me a while (as I was just starting out) to realise why and dropping to less than 30V sorted it out. Of course I was then stuck with the performance it could offer.

I ran with this board for a few years and it did actually work and I could make parts. Would I buy another - not a chance. So you pays your money and takes your choice.