I've recently switched from using the very fine Log4PHP logging library to the Phalcon logging facilities, and generally it's been fairly painless. The one real pain point I HAVE had was that Log4PHP would do the RightThing™ reguardless of the data sent to it. Strings would get rendered, anything else would get either cast to a string or
print_red to make it behave. I'm unclear if Zephir has an analog to get this done, but if it does, it would be a nice thing.