Well you guys all nailed it.
The main thing you guys have to figure out is each design has its "inherent strengths" and its personal strengths with its owners/designers.
Inherent strengths are the facts.........#1 style with spread out loops is thinner and more stable by design! Cant be denied.
Personal strengths are just like Gary and the others commenting on how the holster works for "THEM". My Pro is a Summer Special style Wrap around design with a clip/loop over the gun. Its much more convenient than the first style, but not quite as comfortable.
All have strengths and weakness's.....both inherent and personal.
I'm with Gary in opinion on this one; two lops fore and aft of the gun will be the most comfortable, most concealable, and most stable for most people. This is how I carry daily. One loop, two loops, a wide split loop, or a clip directly on the front of the holster body is the original design that has been worn for decades and serves it's purpose. Though it will shift more and can be slightly less concealable due to the extra thickness of the loop(s) directly ovr the pistol, many people swear by it and find it very comfortable and concealable. One advantage- this style can be made to ride deeper than a front and rear loop style; depending on the design and placement of the loop, and not sacrifice good initial grip if the cant is correct. As to one rear off-set loop; I've experimented with it and found it to shift too much for personal liking, even with a good solid belt. I don't see any real advantage to it; unless you're packing a revolver, only want one loop to contend with, and want to keep the bulk off the cylinder.
Just my 2 cents.