Welcome to the Org Hyperbolic. http://www.totalwar.org/forum/non-cg...icons/wave.gif
Both SP and MP have their interesting points which have already been mentioned.
For those who are thinking about trying MP or are a little reluctant, try arranging a date/time with an online friend or three and trying it with some people you know. Or hook up with some of the others in this thread that have been thinking about giving it a try too. I find it much, much easier playing against someone I know as opposed to a total stranger. I have rarely gone online to fish for opponents - I'm almost always meeting someone to play. Chatting before, after and even during a battle adds quite ia bit of fun to the experience. You can't swap battle reports with the AI. You should give it a try at least once. It is a different game than SP battles.
As for hardware to play online, I do have a cable connection but I've played 2v2s with a P2 350 and a (unsupported) Voodoo3 graphics card. The box says you need a P3 750 for multiplay... http://www.totalwar.org/forum/non-cg...s/rolleyes.gif So go for it You've nothing to lose but the battle.