Just ordered this in black and neon green, needless to say I'm pretty excited.  To those of you that own this holster what are you thoughts?  Comfortable? Concealable?
I will be using mine with a G19.

Winner my friend, I have 2 of them with another on the way shortly for a newly purchased Sig. My first one was boring black, so I got something cooler for my Agency Arms blaster. I had it done in Kryptek Raid with the Lime green backpiece, it turned out really badass looking.

They are super comfortable for me, but remember everybody is different so you may have to get used to it. They seem like a big chunk of material when holding them in hand, but once clipped onto the belt they really aren't noticeable. It also conceals great with the claw, even for a full size gun. Let us know how you like it.

That's what I keep hearing, I was searching for a bad review, but I couldn't find one on this setup.  Im pretty fit and appendix has always been comfortable for me personally, but I was just curious on the comfort level of this rig.  It almost seems too good to be true since I will be carrying the gun itself and a spare mag.
Fit and finish on these holsters are pretty good as well I assume?

I just posted a review in this thread.   http://www.ar15.com/forums/t_5_23/165519_Trex_Arms.html&page=3

Fit and Finish on all of mine has been great. No rough edges, no boogered up screw holes, and the Kryptek on mine looks great too. It is almost too good to be true, because I love appendix carry and its comfortable for me. I will caution you though, I love carrying my 19 sidecar, so much so that I ordered another for my 19 with the APL attached. It IS NOT as comfortable for me, mainly due to the extra length of the weaponlight. This is not a problem with Trex of course, I just don't find myself wearing it as much because the end of the light is uncomfortable if I have to sit for long periods of time. For range work and courses I love it.

However I work at night, so I really like the idea of carrying with a light. I ended up ordering a Surefire XC1 and will be ordering a Sidecar to throw it in. I think the fact that it sits flush with the 19 will make carrying it much more comfortable.