Hey Hank...
Well there isn't really much difference between the two, other than a couple of quirks and slight temp differences...
The grained material is Kydex, but Concealex also comes in this pattern. They call it Hair cell...However it is slightly different..
As far as working it,, you will notice slight differences.The end user won't notice really any...
The concealex you see the most of is call Stealth black, and is my personal preference. I have some Hair Cell here right now,,and don't like it much at all..
If you are interested in Concealex,,drop me a note. I can get it for you in Stealth,Hair cell and hopefully soon Carbon Fiber pattern..
ttyle
Eric...