Do you have an example of when Pry was being spotty? I've never had a single issue with it (on Ubuntu, too).
There are certain scenarios where you can expect Pry not to work "as expected" due to the nature of the language. If you expected it to work, it means you're just not acquainted with the tool/language. Same can be said about any tool or language, not just Pry or Ruby.
Don't know if it's still valid, but, when ruby 2 came out pry wasn't working with that. Not just that it wasn't working, it actually starts and then when I print some variable, VM crashes. I spent few hours thinking my code was wrong and finally finding out pry doesn't support the version of ruby I'm using.
There are certain scenarios where you can expect Pry not to work "as expected" due to the nature of the language. If you expected it to work, it means you're just not acquainted with the tool/language. Same can be said about any tool or language, not just Pry or Ruby.