Camino 1.6 is essentially an evolved Firefox 2, with all the attendant drawbacks. It does work pretty well, but it has the older JavaScript and DOM, and it is significantly slower. In fact, Classilla's JavaScript is actually more advanced than Camino 1.6!

That said, it is probably the best option for 10.3, but I'd put 10.4 on the G3 and run something more recent.