I MUCH prefer the VonStavenhaugen "dot-the-i" sights like the Sig and Kahr have. I always thought I was a 3-dot guy until I bought my first Kahr. It was just plain ole easier to shoot accurately with the line and the dot, rather than trying to balance 3 dots together. I'm far sighted, so the easier you make my visual effort up close, the better I do. The more I shoot my Kahrs, the less I like the other sights...
Unfortunately, nobody makes those for other pistols. If they did, all my pistols would have them.
And no, I don't quite consider the XS sights the same thing, although they are similar. With the Sig style sights, you still have the more traditional notch and post sight picture. And for me, the rear line is too narrow and the front dot is too big on the XS sights.
I tried the XS sights on a Glock 29 once, but wasn't crazy about them. Maybe standard dot... who knows.
My second choice is the "other" type of bar-dot, where the bar in the rear is horizontal. It's a little harder to line up, but still better than the 3 dots. All those dots is just too crowded for me.