I have these (in fact I just found the second unit that had the two player link cable deal), and it's pretty neat to play. The best way I would describe it would be an upgrade from the 16 bit version, but not quite something nearing arcade quality. The best part is the controller being an arcade style button layout, which is always nice instead of dealing with a SNES or Genesis controller that really wasn't made with MK in mind.
Plus it's pretty easy on batteries. You'd think something like that would really suck them down, but it doesn't. I remember they only sold for around $20 when first released, and I always see them in used game stores around here for $10 or less. I would say it's a no brainer for anyone who's in to MK. The tricky part would be finding one that has the link cable, since I'd wager most kids who'd play it would lose it in seconds unless you wrap it around one of the controllers when not in use.