I've tried a few ankle holsters, one leather, but the best for me is an Uncle Mikes ankle holster (mines a size 10) with Sig 365. I like that the retention strap is removable so it can be positioned any where, and at any angle that best suits the retention of tool you have.
I also like the calf strap (it is removable) which allows me to keep the holster up and from rubbing on my ankle bone. I added a little piece of wool on part of the calf strap Velcro strip because my leg was large enough that some of the hook part of the Velcro strap did not overlap enough so rubbed my leg. It is totally adjustable, can be used for similar sized guns, plus, as it ages, it can be readjusted and not just tightened up like some I've had.
Mines positioned like this;
The sock is important to me, I use a cotton wool blend which ads soft comfort and found the heavily ribbed top cotton ones not so good compressed to your ankle and shin over time.
I used to wear it 9 to 10 hours a day for over 10 years. Originally with a snub 357 sp101, then a Glock 26, now the Sig.
I might add that I have never felt sore with the Glock or Sig. When I put it on it feels snug and warm at the beginning, then fades into obscurity after 10 or 15 minutes though originally, the weight and hard lines of my first ankle carry the Ruger SP101, could be uncomfortable after a few hours but not unbearable.
I can't do IWB, so my preferred carry, OWB, are all leather, self hecho a mano, since I best know what works for me.