I DO use a "NO CLEAN" flux, but I still use the .031 rosin core 63/37
Since you need to clean (even after using "No Clean"), I prefer the extra benefits of the nice shiny solder joint that the rosin brings with it. Dewetting is a minor issue with the rosin.
Did you also know that you are supposed to trim your leads BEFORE soldering the joint??? Do a quick demo for yourself. Take a piece of the lead you are going to solder, and place it on the pad and trim the component lead the thickness of the piece you put on the pad (you can lay your nippers on the piece so you can gauge how close to trim the component lead). after trimming the component lead one thickness of the lead itself, appy flux and flow the joint (especially the exposed copper of the lead you just cut), Now, compare the sexiness of that joint compared to a solder joint you flowed prior to trimming the lead. You can see the stresses applied to the solder joint just caused by trimming not to mention the exposed copper left by trimming after soldering.