I dunno, a couple of things throw me off about those mids. The thin kevlar cones that they say "Flex to make a softer form of distortion than the popping made by traditional poly cones" also means reduced bass output. The stiffer the cone the better material it is for bass reproduction. That is why in subwoofers they always use thick pulp paper, thick poly, or solid spun aluminum or other metals.
Also i don't know much about this new magnet system they talk about, but maybe it limits x-max in some way. I know it is kinda an underhung design in a way. I couldn't find any x-max or xmech specs on that component set though, maybe it is in the manual that came with them?
EDIT:
Really though after looking at the aura subwoofers using the same technology nrt motor that have 2" peak to peak excursion I don't think the xmax on those would be a problem. Have you heard other people with them? What kind of vehicle are they in?