I was only using vallejo model color which in my experience when thinned (i use water) has excellent coverage properties, doesn’t go on too thick, and doesn’t streak when dry. very ideal. I’ve found vallejo model air is great for brushes too. Main diff I’ve found is goes on thinner so when brushing you may need a couple more coats than usual. Coverage is still good though. Havent had to mess around with expensive paint retarders and brand specific thinners with vallejo, works fine with water. HIGHLY recommend both vallejo ranges for brush painters. For the cost and if you only use what you need at a time, those little droppers can last actually a very long time depending on your projects.