[syslog-ng]Syslog-ng Reliability

Well, I got syslog-ng setup and running. Runs great. I have to say, this is a realy nice way of doing logging. Major kudos to developers. a few questions: 1. How reliable is network server operation of Syslog-ng under heavy load? I am running remote servers using tcp() and anticipate a lot of throughput. Will syslog-ng not drop stuff like syslogd does? 2. log_fifo_size(100) is this in bytes or kbytes or what? Is this a memory buffer before a write is done? 3. I didn't find the documentation in the man page for variables like $YEAR, $MONTH, $HOST, etc. Where is the list of these? 4. Any idea when compress(on) function will be implemented?