Nice exceptions overview :)
"It was written to cope with Exceptions, introduced in Zend Engine 2 as the error handling mechanism."
-1 from here, I do not like the idea to force the usage of exceptions as general errors hanlders.
I failed to see why each single package should declare (or extends, or...) their exception classes. Why? I can imagine some without any kind of exceptions...
"An error is defined as an unexpected, invalid program state from which it is impossible to recover."
This is the definition of an exception. Where exceptions should be used (trying at least to die cleanly ;) ). But in no way the definition of an error. That's exactly where errors and exceptions differ.
Sorry, but -1 from here.