If there's anything I've learned, one extremely important rule to follow is that each area of a map should bring something unique to the table, so I'm running a massive brainstorm to get some cool ideas to build around for the 2nd stage. So far it looks like the first cap will be focused around a watermill, and the second cap will be a massive sawmill (not copying the map sawmill, but there will be at least 1 saw, I hope), both connected by a central river.
In general, I like the idea of building a map around using water as a viable and actually useful tactic thrown in amongst the usual shoot-kill-spawn-repeat stuff.
The "interesting idea" approach was what I used on the first stage, and I'm incredibly happy with it. My friends and I played on just the first stage for 2 whole hours and somehow it didn't get boring. I have high hopes for the 2nd stage, but I've got life interfering as well.
Rest assured though, I will not abandon this map.