I find it highly implausible. Most likely OP ignored the full context of the statement. I can't imagine any of my co-workers recommending Java Maps over PHMs ex

I find it highly implausible. Most likely OP ignored the full context of the statement. I can't imagine any of my co-workers recommending Java Maps over PHMs except in very rare interop situations. Likewise, I can't remember the last time I even saw a ConcurrentHashMap used in Clojure code, or STM for that matter. Most of the code I write, and work with, is as recommended for years: Persistent data in as few atoms as possible. No ill-will directed at the OP, but it's hard not to take umbrage at the suggestion that I am a snake-oil salesman. So yes, references please!