Interesting discussion, guys! I've only played Ludwig hi-hats and here is (are?) my two-cents worth....The 1121 and early 1123, with the three legs splayed out flat on the floor are troublesome. They "walk" forward on me, and I have to tie them to my seat. The 1121, in my experience, is not stable. It tends to wobble.
The 1123-1 is a good hi-hat, nice and light, and does the trick. I use one now. My only complaint is that the spring tends to get weak with age, and if your high-hat cymbals are the least bit heavy, or if you are using 15" cymbals, the "action" will sag downward a bit. In other words, the footboard won't rise up all the way and thus the top cymbal will sag downward a bit under its own weight.
The 1124 Atlas is my favorite. I play a 1124 regularly. The advantage is that the spring tension is adjustable, and it also has a little spur (pointy thing) that can be adjusted to stick into the floor or carpet to keep the high-hat from "walking" forward on you. The only weakness I have found is the link between the footboard and the "action." One variety has a light-colored (whitish yellow) hard plastic link which will fail eventually. The other variety has a steel link which will not fail. Enjoy!
Regards, MB