The choice is not the paint in this case, it is the painter. Choose whom you feel will give the better end result at the better number.

How does the middle of the line on each brand compare? Cost per gallon? It's more useful, arguably more accurate, to price it out price per square foot, not per gallon. Read the label to find out how many square feet the manufacturer says the gallon will cover. Divide the price by the square feet. Coverage and hide are not the same. A gallon may cover "x" number of square feet, but the color selected will determine how well it hides. It's really not fair to make all-encompassing judgments about a specific brand of paint because many things contribute to how well a gallon performs. Every brand has positives and flaws. The color dictates a lot. In other words, the same color in another brand would not hide any better - so it's not the paint, it's the color. Prep of substrate also makes a difference. If prep isn't done correctly, doesn't matter what brand you use, it's not going to end well. Bathrooms are notoriously difficult environments for any brand of paint. The streaking is normal; it's called water whitening. It happens with lighter colors too you just can't see it like you can with darker colors.

Also usually a BM loyalist (Regal Select is my fave), but just recently broke with that and used SW Emerald interior matte to repaint a bedroom the previous owners had painted a DARK, almost black Navy. The Emerald was recommended for covering the dark with a much lighter color (Sea Salt) and since the coupon brought the original crazy high price to the same/equal to what I usually spend on BM Regal, I went with it. I was (am) impressed with the coverage and the paint formula in general, 2 coats and the navy was nowhere to be seen.

Why not just use the Behr so you make sure it is the color you love.