.....jeepnik, I envy you......back in the mid-70's I got a Sparks Yaqui slide because Jeff Cooper made them look just so uber-cool! I still have a couple of them and they're getting stupid-$ for them on ebay. My problem with them was two fold:
1. A number of times I'd sit down in an armchair and brush up against the arm as I sat down. The arm of the chair would hit the muzzle of the gun and as I seated myself, the handgun would be pushed up and out of the holster; no doubt that's more a factor of my fat butt than of poor holster design, but it happened numerous times.
2. The second problem I had was that during the draw stroke, if my elbow didn't come straight back and then hug into my body, the gun would cant as I drew it and the gun would basically be twisted slightly and the muzzle wouldn't clear the holster. Again, a function of a poor draw, not poor holster design.
I watched Cooper and others draw from their Yaqui slide just as slick as snot on a doorknob and have been envious of guys that can use them ever since. I just could never master it (or them).