I've made a small module with a town, a small catacomb quest, and a small "kill the vermin" quest. It took me the good part of
a day though. Now that I've done it once though, I think I could churn things out much more quickly.
My favorite part was that I was able to script the purchasing of a room at an inn. You can't rest anywhere but in a room that you've paid for, and even then... you only get to stay for a night.
Really, really flexible environment with scripting. Plus, if you help out the family that owns the inn, they let you stay for free.
A couple of tips for builders:
1) Make a flowchart for EACH QUEST WITH QUEST VARIABLES. When players enter, set quest variables to 0, and as they progress along the quest, increase those variables. The chart helps to keep track of what variables you need.
2) The city has a whole lot of doors. A whole lot. Make sure you fill them all in, and make doors that you don't have houses for be plot, and super high DC locks. (I'm going to have to write a script for a generic house... Shouldn't be too difficult.)
3) Encounters are pretty cool. Learn them, and use them.
Once you give up your deathgrip on the control of what monsters are where, you'll see how adjustable it makes your world.
Careful where you put your spawn points though, especially if your dungeons allows someone to go BACK a way they didn't come.
After all that work though, I found out last night that I couldn't host a game on the Internet... There's a NAT in between me and the internet that I'm not in control of... Hopefully it'll be fixed sometime this week so I can DM a game finally!