I've been using LinuxCNC quite happily for a few years now but want to get away from needing a dedicated PC in my very small workshop, especially one requiring an antiquated parallel port. I've also found that the pulse timing from this machine, as with any controller relying on a conventional operating system to calculate when the pulses should occur, to be less than perfect and I'd like to see what improvements to noise and vibration I can get from a dedicated controller card able to produce accurately timed pulses.
I am not sure why you sure why knocking linuxcnc saying that it "especially one requiring an antiquated parallel port" as that is not true. Stick any Mesa card in it and you will have pulse timing as fast and accurate as you will need. If you want Ethernet connected card then use a 7i76e card.

There are plenty of options for other motion controllers as well