I paint with both as well and like others, some colors from both ranges I prefer also. Prussian blue and balck are good ones. Actually, I like all of Andrea's blues. I wish I could tell you more but it really just depends on what color I want. I look at the bottles, figure out what colors to mix then paint. Sometimes (frequently actually) I mix colors from both lines to get a desired effect. Additionaly, I have found Andrea paints to be thinner than Vallejo needing less water for highlights and shadows than I need for Vallejo.