In the expensive and time consuming quest to find a comfortable, quality, IWB holster I found the ONYX from StealthgearUSA. Stealthgear has made a holster that took the dual clip leather with kydex style holster to the next level. The biggest difference between the ONYX and others is that the ONYX uses breathable Vortex material and padding, so there's no more sweat building up due to hot skin on leather like other IWB holsters. I've been wearing the ONYX with my M&P40c for about 3 months now, and this is hands down the most comfortable IWB holster that i've used. Breathable material, padded, adjustable positioning, and lightweight.
Check them out at stealthgearusa, and on facebook too. I know that they have a discount code going right now of, "carry on", for 10% off.
If anyone has any questions about this holster hit me up, I wear mine all day everyday. I've even taken naps and not felt the firearm and rig at all. I used a Crossbreed Supertuck for several years, and never had any complaints. This ONYX takes it to a whole new level of comfort that I wouldn't have though existed.
I can't seem to upload my photos at the moment; I'll try again later.