If you're using Debian or Ubuntu especially, there are a number of benefits to installing Tor from the Tor Project's repository.
ulimit -n gets set to 32768 high enough for Tor to keep open all the connections it needs.
- A user profile is created just for Tor, so Tor doesn't need to run as root.
- An init script is included so that Tor runs at boot.
- Tor runs with
--verify-config, so that most problems with your config file get caught.
- Tor can bind to low level ports, then drop privileges.