I have gone to Stan's. I have gone to Randy's. I have gone to Bob's in Farmer's Market. I have gone to Primo's.
That said: my standard for the "light" doughnut is Krispy Kreme unglazed. My standard for the "heavy" doughnut is Dunkin' Donuts blueberry.
I went to Randy's. Good texture, nice flavor - the twist definitely had that touch of bake-y sourness - but felt a little rancid, a little oily.
I went to Bob's. I have no memory of Bob's.
I went to Stan's. The textures aren't quite as lovely as Randy's. No rancidity, a good donut, but not quite any sparkle. The sweet flavors are one-note, fatty but the fat's a little... listless in flavor.
I went to Primo's. The next day, I somehow justified a trip 20 minutes in the opposite direction of home, to a Best Buy - despite the fact that there's another one on the way home - because Primo's was nearby.
Primo's twist has that breathy, chewiness that I expect from a light donut - and that nice fresh sourness, but a really deep sourness, once that wraps around the mouth and settles in for a while.
The buttermilk is really beautiful. A beautiful crumbly/chewy thing, and has a substantial, earthy flavor.
I can't really understand why Primo's doesn't come up more in general discussion. Besides the one thread here. I mean, Randy's has the schtick, and Stan's and Bob's are in very heavily travelled areas - UCLA and the Farmer's Market, respectively - and Primo's is on a strip mall in the middle of nowhere.
I went to Stan's after two straight days of Primo's - first time in my life, got donut cravings - and it just was flat.