I am writing my first objective-c daemon type process that works in the background. Everything it does needs to be logged properly.
I am fairly new to Apple stuff so
Another alternative you might want to try is https://github.com/CocoaLumberjack. Lumberjack is quite flexible and will allow you to log to various destinations, configure log levels, etc. It's very log4j / log4net like, if you are familiar with those.
It's also reports that it is faster than ASL... I don't know how it compares to GTMLogger with respect to functionality or speed, but the documentation seems to be a bit more approachable.