OK, this my FIST #K8 for my M40-A1. The pics FIST does are accurate, in that FIST Kydex holsters are not glamorous looking. I have also already modified it, and I ordered it with a modification.
Look at this pic of the basic K8. Notice how the attachment starts at the bottom of the belt, and travels up to the belt attachment. The belt attachment attaches with screws and is removable, so you have a choice of attachments: J-hook, belt loops, slotted loops, etc.
Personally, I don't see the point of using a tuckable holster if you have the the dern screws visible and poking out 1/2" to 3/4" above the waistband. So.... I ordered mine with J-hook, but made in one piece, without the attachments. I asked for one piece of Kydex that attaches at holster bottom, extends up and is folded into the J-hook. Basically in the style of this clip, on the K4:
OK, so far? Well, the K8 is "cantable", meaning the front screwhole at the bottom is slotted, so you can pivot the attachment and adjust cant. Now examine that first picture again. If you "mentally" move that belt attachment to the left of your screen, the way you would for a forward "FBI" cant, guess what happens? Why, that belt attachment is now in front of your pistol handle, as I discovered! That ain't no dern good, at all. In addition, the holster rides too low on the waistband, and to me it seems like it wants to dive below the waistband. So I can't get a good grip on the pistol. Not good.
So...out come the tin shears and Dremel tool. I unscrewed the J-hook, clipped the kydex off at the top of the "slotted" screw hole, then laid that piece over the remainder and used a Sharpie to mark the outline and the screw holes. A minute with a file finished and rounded the cut edge, and a drill bit and Dremel with router bit finished the screw holes. I am just a hack at DIY, but I did considerably neater work than FIST did.
Here it is with my modification. The cut-off piece is visible at the bottom.
Here is a
Big Pic for detail.
The gun is held tight to my body. Concealibility is good. Draw is fine, being so tight to the body means getting thumb in for the grasp is more work than an OWB, which is fairly standard for IWB. The comfort seems adequate. More comfortable than my CompTac Shirt Tucker for my Kahr PM40 was, for me anyway. It is less comfy than my Crossbreed IWBs for M40 and Kahr PM40. A smidge more comfy than my SideArmor IWB for 5"1911. I think I prefer the stability of 2 points as in Crossbreed, Sidearmor with outrigger, CTAC, etc. This is especially the case since the single J-hook causes soft waistbands to sag. OTOH, it is much easier and quicker put on this holster than it is to put on those others with 2 J-hooks.
When I use the "split J-hook", and install it around a belt loop, the "saggy waistband problem with cargo shorts" goes away. Since I also shortened the "shaft" of split J-hook the same way as I did the first J-hook, the holster now rides a but higher and is considerably more comfortable. When using the split J-hook around a beltloop, it takes about as long to put on as a 2-point holster. With a T-shirt as an underlayer (between holster and skin), it is comfortable enough for full day wear.
It's not pretty, but it's not for show. It does seem solid in construction, which I like.
Bottom line: I like it.