I took my KSM to work and I thoroughly enjoyed it. So easy to refill.I just spent a couple of weeks traveling. Didn't want to bring RBA supplies, so I reverted to my Aerotanks and extra coils. It wasn't that bad, but I would sure like a better travel atty. Not sure if the Subtank Mini would become my favored everyday atty, but feel certain that the Mini or Nano would be a huge leap forward as a travel atty. If only for that reason alone, I will definitely be taking the Subtank challenge.