I prefer Fiamme reds to blues because they have ferrules, which IMO makes them more functional. Plain no ferrules rims can be fine though. Anyhow, I liked Fiamme reds just fine and they were my everyday rim for years. I found them tough enough and more or less similar to the other tub rims of the era at that weight. At any rate there were not any ~350g clincher rims to compare them to at the time... Certainly they were tougher than Rigida 1320.

I'd imagine more than a few sets of Blues and similar vintage rims have been ruined because the builder didn't use spoke washers. Most likely younger builders never heard of them. That could have been the case with the OP's rims.