OK...Updated review...I've been using the Intruder holster for well over a month. It gets worn every day...A fair amount of standing/walking and lots of driving. I don't wear it at home (mostly) and don't wear it at work (on duty) but if I'm out and about, the M&P9C and Desantis Intruder have been going with me.
First a quick summary:
Pro:
Comfortable, retains form (easily re-holsterable), good retention, consistent draw, sweat guard, adjustable.
Con:
Overall large size, hard to put holster on quickly.
The rundown:
As I said earlier, to me this type of holster just looks "too" big and uncomfortable. That's deceiving because they are very comfortable. I've worn the holster while sitting during an 8hr seminar, for hours and hours in the car, and while walking around stores, etc. The pistol stays put and the clips seem very secure. I don't have any concern about drawing the holster with the pistol.
One of the biggest advantages of this holster is due to the widely spaced clips and large profile. The holster simply doesn't move in terms of depth or cant. I can slide it around on my belt if I need to but it stays put. Many other holsters move or rotate a bit and I find myself pushing the butt forward or back and adjusting it quite frequently. With the Intruder I never have to adjust the position because it is rock solid. Once you find the adjustment you want it's going to be there every time. Nice.
I even used the "tuckable" feature of the holster once when receiving an award at a dinner. it worked surprisingly well.
I thought the holster would work better than others without an undershirt (t-shirt and jeans type stuff) but it was about as irritating as other holsters, which is to say it's doable but not my ideal. When wearing an under-shirt with a button-up (official off-duty cop uniform...) I have to say it is the most comfortable holster I've worn. Even the con of it being difficult to put on has improved greatly. It takes some practice, but once you know the technique it's not a big deal.
I haven't used the holster with the full-size M&P, but I'll be purchasing one soon (9mm) and will try it out. Of course, I have to get to the shop to get it and wait the 10-day "I already own multiple handguns but this one might just drive me over the impulsive edge" waiting period, then test it, so it will be a while.
Here are some pics: