It's rare to encounter a steel framed bike at any quality level that is actually bad to ride, which is different to my admittedly limited experience of alloy frames. I have a real cheapo Puch 3-speed with swaged gas pipe stay & fork blade ends electrically welded to the dropouts but it still rides very nice. That said I do much prefer the 531 and 501 frames myself, but even a gas pipe job can be great if the geometry is half decent - and diamond frames have been around so long now that you'd have to try pretty hard to come up with a poor set of angles and proportions. Trial and error produced the optimal frame design decades ago and all you get now is a few more ounces off the scales and a bit more give and a bit less girder like feel.