It has held up great.
After adjusting the tension, it can hold up fairly large devices without any problem. I was using this for over a month with a much larger 22" LCD, and it was stable as can be. At this time I also had the Gateway FX 17" notebook on it, and worked fine as long as spring tension was maxed.
Right now the stand works as good as it did on day one, although I have had to retighten one of the pivot points more than once on the monitor side. I frequently spin my LCD around to show Jerry things from time to time, and one of the screws just gets kinda loose after a while. In a normal home setting this would never be a problem.
The dell 24" should be fine, as its weight is around the same as the Lenovo 22" I was using.
The only thing you need to worry about is the desk surface you are clamping this thing onto. My work desk is like 1"+ thick, and with the weight of LCD and notebook it can flex the entire desk surface. If you are putting it on some 1/2" pressed fiber Sauder desk surface it would have a high chance of ripping your desk in half and throwing your equipment on the floor
