Are you using PS and creating different layers for buildings?
The one city map looks like Mos Eisley from SW Galaxies MMO, almost to a tee. Great Work!
I do all of it in photoshop, been using that for over 20 years professionally, though i have tried other programs for fun, I just always go back to it. Thanks for the compliment on Eisley, man i do miss that game, but pre overhaul... when they tried to be WoW, i finally had to give it up.