Updated to Ver 1.1
Well, I recently completed my very first level using Doom Builder 2. It's somewhat small (takes about 2:00 to complete on UV), but it was designed small to be closer to a basic E1M1 or MAP01-style opening level for an episode. I'm also fairly new to monster/weapon/item placement so I apologize in advance if it's too easy/unfair. I'm going to be working more on getting proper monster placement in the future.
Anyways, here's the map's "specs":
And here's some screens (taken on HMP):
And of course, the link can be found here: http://bit.ly/JR-01-03_WAD
(and if that ever fails to work, another two below)
(changelog for those interested)