As a friend in Texas used to say -- WHOA! :-)
Yesterday I made a loaf of barley bread from the Bob's Red Mill site. Now, bearing in mind it wasn't a sourdough-based recipe, which may have made some difference in the rye and wheat loaves by converting some of the carb to acid, it REALLY did the ol' blood-sugar-spike thing! A full 20 points higher than the other gluten-grains I tried!
I didn't even like it as well, though my husband did. Even though the barley flour contained "no" fat, it had a smell that I associate with rancidity. I'm willing to eat evil things from time to time, but only if they're luscious.
All this is going to make it VERY easy to avoid barley-flour products. However, I do still like pearled barley in soup. I guess i'm going to have to run a similar test on intact-grain barley as compared with rice.