Chuck,
I absolutely agree with you. Everyone should try flying circuits by attitude. I've had two ASI failures.
Once in a 182, at Red Deer, due to a mud-wasp's nest, when I didn't notice the lack of needle movement until after takeoff
, so a quick circuit was required.
And once in a Scout at Claresholm, where I noticed it during the takeoff run, but because I had a ballasted Open Class glider behind me, I decided that continuing was a better option than risk having the glider run into me during an abort. It turned out to be water in the pitot line, which cleared itself during the tow.