Is D3 worth the $55 upgrade from D2?

[Edi]

As someone who played both Dom2 and Dom3 extensively, I will say that it's definitely worth it.

There are tons of new nations spread across several different eras. There are more maps and the modding capabilities and possibilities that the mods open up leave Dom2 looking like a beggar in comparison.

Furthermore, a lot of bugs that are still extant in Dominions 2 have been fixed along the way in Dom3, which means the game is more stable. You can get an idea of what all has been fixed by taking a good look at the bug shortlist stickied at the top of the forum.

And the AI knows how to build castles! If you're into SP, that's a huge deal. In MP it's not an issue.