I use a Smartcarry low at the 1100 position. Nice thing about having the gun in front of you is that it minimizes hand movement when drawing, compared to more traditional 3 or 9 o'clock carry.
While the Smartcarry puts the handgun lower than other appendix holsters, it allows you to tuck your shirt behind the holster. Thus, what you lose in time by reaching further down, you gain by not having to untuck or sweep away a cover garment. Plus, you look neater, and no-one will suspect you are carrying a very substantial handgun (no need to compromise and carry a mousegun with this holster).
As far as sitting - when I sit, the gun lays on top of my left thigh. Very comfortable, though I would imagine a 1911 beavertail might get a bit pokey. I carry a Glock 26, so no worries about pokey bits and sharp corners. My wallet in my front left pocket helps conceal any printing while seated.
Give it a try - you can return it if you don't like it.
I tried "true" appendix carry, and between my belly pushing the gun out and thin dress shirts for work, I might as well have worn a sign that said "look at me...I have a gun!"
