From my friend Rick:
If I could please have your expert opinion on benchwork: I had originally planned to mount my benchwork to the wall using similar methods to what you did. That has changed due to our recent experience mounting our TV to the "studs" in our master bedroom. First, I found that the "studs" were on 24" centers instead of 16" centers. This isn't a big deal; however, the dimensions and connection method of the "stud" is. I went over to a house under construction and discovered that the walls against the concrete block are NOT studded with 2 x 4s, but instead are covered with furring strips approximately 5/8" thick by 3/4" wide AND these strips are only held on the wall by 3 concrete nails. While these furring strips are fine for holding drywall I suspect the will NOT be strong enough to handle the pulling force of a shelf layout not supported by legs.
So, I'm thinking legs for support and screw it to the wall for stability. I sent you pictures from my iPhone. Your thoughts, please.
Ouch! This could be a problem. You aren't going to get enough "bite" with a screw to hold anything. My first thought is to go with stand alone L-girder and leg construction. My guess is that your interior walls are studded, so you would only have to do this on the one exterior wall. All the rest would be studs.
I see that Zorro was there!
Others...if you have ideas, shout them out!