Well as topic starter I think it behoves me to report how I went. Visit completed.
The CS's that most impressed my guest were Club Media, La Tertulia and Yo Yo's. Given his frame of mind and stance on the weed issue - there were many that didn't impress. Barney's probably would have made the impressed list but they have a weird laptop and internet access policy there. We were asked to turn our laptop off and not access the internet while in Barney's. Quite rudely too I might add.
My guest was a little enlightened by the relaxed culture, but he couldn't be swayed to adopt a more supportive stance on laws back home. I seem to remember a poster to this thread was suggesting that could be the case.
All in all, I got a lot out the visit, my closed minded politician friend could not quite grasp the concept of harm minimisation. Nothing gained from his perspective.