I bought a Raven modular holster system about 2 or 3 months ago. Jay, the owner (one of?), was very helpful throughout the process of figuring out what I needed, as well as being willing to experiment with something he'd never made before, but that I knew I needed/wanted.
With Raven's modular system, you can have screw-on adapters to make it a belt slide (standard with order of a "Phantom" rig), a pancake, or an IWB with clips ala Comp-Tac, K&D and Crossbreed. I use a Crossbreed for my RAMI with V-Clips attached to a Belt Man belt with Velcro sewn into the usable length. I wanted the Raven with V-Clips as well, but they didn't offer them. A few emails solved that though, and Jay assured me that, for a very reasonable added cost, he would make some, and remake them until I was completely satisfied.
The first set he sent didn't work for a couple of reasons, which are really irrelevant because they're long gone and Jay, true to his word, completely redesigned and remade my V-Clips, which I just got yesterday. I am here to tell you that they are perfect! In fact, they are perfect x's two, as he included two sets with two different kinds of Velcro for me to try. I have only tried the ones that were attached to the mounts so far, but as you'll see, the ones that I haven't tried yet, the Velcro looks pretty darned stout.
I already have several holsters for my S&W 4563TSW, including paddle, belt and IWB varieties. A couple of my belt holsters are made for use with a light/laser attached, but they obviously don't conceal very well due to the bulk. Since Jay was willing to make his Raven rig work similar to my Crossbreed for my RAMI, I figured what the heck, I may as well get an IWB holster that will accommodate my TLR-2. The worst that could happen was that it would be too uncomfortable and heavy to tote that way, but I'd still have a workable belt and pancake rig, so I went ahead and tried it. To tell you the truth, I was expecting somewhere between just barely tolerable to completely intolerable in the comfort dept. To my surprise however, there is very little difference in comfort between the Raven/Smith/light and my Crossbreed with my RAMI in it. The Raven is shaped just like your hip, making it ideal for how I always carry anyway, at about 4:00 - 4:30. It hugs your body in all configurations, but obviously hugs best wearing IWB. The IWB adapters are tuckable just like the Crossbreed Super-Tuck, but I didn't go to much trouble to make a good example of how well it works in the following pics. I got home from work, got the package, installed the new adapters and just threw it all on in a hurry to take a few pics. The bulge is very evident and there is some visible printing in the tucked pics, but I'm very confident that I can fix that with the right shirt(s) and making some minor adjustments to the positioning of the holster. Besides, even with the Crossbreed and RAMI combo, where there's almost no visible printing or bulges when tucked, I still don't wear it that way any more than is absolutely necessary, nor do I plan on doing anything different with the Raven. I just wanted it as an option and Jay was very accommodating.
Anyhow, here's some pics. I'll answer any questions I can, but if you are interested in seeing more from Jay and Raven, go to The Malabar Front to look at their rather extensive line of concealment products. The Malabar Front website is the retail side of Raven Concealment Specialists and owned by Jay and whoever his partners, if any, are.
With shirt tucked in behind holster. Notice that the V-Clips are 100% invisible in these two pics. If I had spent any time really preparing for the pics of the rig with a tucked shirt over it, both clips would've been invisible in those too. I can discern no difference at all in the stability of either this holster or my Crossbreed between using V-Clips and regular, over-the-belt standard clips, but the gain in concealability is in the 100% range. I can't recommend them highly enough.
And the extra, alternative kind of Velcro. I should've taken a pic of the profile to show you how high the hooks extend from the base material. I just didn't have time to go back and start taking pics again, so just take my word for it, the hook part of this stuff will reach a good ways into the loop part on the belt and be as secure as any Velcro fastening system can be. I will install them later on, after I've had a chance to really evaluate the ones I have installed now, and come and add anything to this review that I think is pertinent.