The thing with MKX is that it was designed with a regular controller in mind: 4 attack buttons only and special moves catered more to a dpad. So IMO an arcade stick won't make as much of a difference.
Play an older SF with 6 attack buttons, and more joystick-focused special moves, and you will really see the difference.
I've got a couple of Virtua Sticks for my Saturn, with an adaptor for my Dreamcast as well. I've used a handful of friend's as well, including a homemade stick using proper arcade buttons in a lunchbox.