I used it too for a while, as a mandatory corporate thing. Always kept it disabled! No problems. Got rid of it when switching to Leopard.
On one machine (PPC), I use ClamXAV (don't like it because it is very slow to update, and it does it every time I download something and it starts to scan), and iAntiVirus. The latter is my favorite - fast, unobtrusive and, by many reviews, reliable. Unfortunately, it won't work on a PPC, only on Intel.


Alex
3.1 GHz 13" MacBook Pro 2015, 8 GB RAM, OS 10.11.2, Office 2011, TimeWarner Cable
2.8 GHz Xeon Mac Pro 2010, 16 GB RAM, OS 10.11.2, Office 2011, LAN