Well, before i got the 14-24, i was using the Lee foundation kit, so if you compare the 2, the Fotodiox is a much larger, bulkier and clumsier solution, but i guess thats what it takes. the build quality is top notch, but I've been disappointed with the quality of Fotodiox ND/CPL filters, or all of their 145mm threaded filters for that matter. they are not multicoated and when shooting into the sun, they will cause reflections and flare like nothing you've ever experienced before. In certain conditions they might cause light leaks in the corners too, but that can be fixed with relative ease in post
i was told by their support they are working on the multicoated versions of the filters, i hope they come up with the solution really soon.
I know several photographers who use Lucroit system on their 14-24, but i've been burned by Hitech QC before, so i went with Fotodiox this time. Hitech do make GND filters in sizes compatible with Fotodiox though
I'm working on a very extensive review for this system which should be publishes at my website when it's done, might take me a while though