Even coverage is everything
Obviously, in an ideal world, one would cover everything with a thick coating in one pass.
No, I'm not talking about how our famously free press covered the primaries, I'm talking about latex paint!
Bringiton's theory, if I don't mis-state, is that latex paint, being water based, really is like water color, and that one gets even, rich color by laying down coat after coat, like thin glazes.
In the abstract, he's right. And if I'm painting a room for me, that's how I'd do it. But if I'm painting a room as a quasi-commercial proposition, the labor on multiple coats is killing me. Two coats, max, should lead to even coverage -- even when laying down a lighter color over a darker. Is that possible?
Leading me to roller technique. I did my first work on unpainted, bare drywall (with the Zinnser B-I-N-S!) and the drywall seemed to soak the primer up, plus the primer, being shellac-based, was very drippy.
So, the only way I could work with the roller was to really work the primer down into the surface, and keep rolling all of the "ridges" left by the roller edges were flattened out.
I then carried that technique over to the latex -- work the paint into the surface, keep the coat as thin as possible, with the side effect that thin coats mean no ridges.
So we come to the current room, where I'm painting lighter (like semolina) over darker (like mustard). I used the thin glaze technique for the first coat, but the coverage was uneven. When I tried the same technique for the second coat, coverage remained uneven. So, rather than multiple passes over the surface, I tried for minimal passes with a thicker coat, always rolling into the wet edge. Seems more successful, but also uses more paint.
NOTE As soon as you figure out that paint equals money, the advantages of painting with a Zen-like calm, with no drips, spills, or mess, become evident. Being calm helps when lining in the borders between colors, too. (Tape also equals money.) I tested my new-found skills by painting the wall under some cabinets with brushes and rollers -- over a formica countertop with no dropcloth or newspaper. Not a drop lost!