I figured that I would add my response to your question here, as the last half is actually is a question for you. 
I have not played Age of Mythology, though I have played Age of Empires 1-3 and enjoyed them immensely. I still remember playing the first Age of Empires for hours straight when it first came out.
What are your opinions on Age of Mythology? Do you think that it would be a worthwhile addition to my game collection?
Yes, it would definitely be a worthwhile addition to your game collection. It's kind of a "must have" if you like this sort of games, actually. That said, I gotta admit that I like the game less now than when I first played it.
Don't get me wrong, it is a very good, solid RTS but... in all the time that's passed since my first playthrough, I'm actually starting to see some of its mechanics as "not as great". For example, you have to build a temple in order to summon mythological creatures (which is not bad) but you also have to put some of your villagers to pray on them in order to gain favors from the Gods... and if you don't have those villagers praying, you won't be able to summon anything (and in a game with "mythology" on the title, that would be a big letdown). That's not really bad, but it is annoying and it forces to keep training villagers just to have minotaurs and the like on the field -even though you could easily win the battle with normal troops-. Thankfully, some civilizations don't require you to do that.
I'm also not a big fan of how quickly the computer moves on the higher sets of difficulty... raise the bar just a little and you would find yourself being under constant attack (or at least "espionage") before you even know it. That's again not bad, since it presents a good challenge, but it can be a bit overwhelming.
I have some other pet peeves, but nothing THAT big (and the game makes up for them with its strategic side, which I actually find tremendous). Oh, and the online community for the game is actually amazing, some of those battles make you like if you were on the field just because of how intensely they are fought.
