I never cared for them for pistol mags. There is a AR15 mag loader that I used years ago when shooting with a friend and can't find now. It fit on top of the mag, you dumped 10 loose rounds in and push the button and bam they were loaded in half a second.
I did have a P226 mag that was a pill to load the 12th round in, I did use a speed loader for it. After a while it no longer gave me problems.