Finally pulled the trigger and bought the game/expansion. I jumped straight into the expansion and skipped the campaign in the original game. I am really enjoying the Dragonfall Campaign, and I'm a tough sell. I probably only find 3-5 games worth my time per year and this definitely makes my list. It's very well written, the characters are deep and interesting, and the pace and progression are pretty close to perfect. I never played Dead Man's switch, so I can't compare this with that, but I'm really loving Dragonfall so far (probably 12 or 13 hours in).
When I'm done with Dragonfall I plan to check out the map editor and try to create a campaign set in my home city.