I have a 105 with 44-34-22 and an Ultegra with 48-38-24 and they both work without problems. The only slow move is going up from 22 to 34 (and it's not that slow, just a bit slower than other moves). So if you already have the derailleur, it's probably a good choice. One thing I need to highlight, is that I use bar-end shifters, which means I shift the front end in friction mode. As Sheldon said, with STI it might be different (though I'm aware some people were quite successful).

But there is another issue not covered so far. Is it for new rings you are installing on a crankset? If so, if it is a Shimano crankset, it uses 130/74 mm bolt diametre and accepts 38 mm and 24 mm as the smallest middle and small chainrings.