LTM/GTM logging

Syslog is generally configured to roll logs over after a point, so disk space shouldn't be an issue. The one thing you should consider though is that standard logging runs in a syslog service in the management plane, so passing doing a lot of logging from the data plane into the management plane can create performance issues. If you're going to be doing a lot of logging, use the HSL (high speed logging) process, which uses tmm to send remote syslog messages quickly. Now, as far as usefulness, that as Cory says, depends on what you're looking for. There are more than just LTM and GTM logs on any given platform, and a wealth of information that is either built-in or that can be configured.