This is my first Luxrender scene in about a year now, went at it again, hope you like it.
Check both previews, one is during the day, the other is during the night and with atmospheric lighting, although couldn't get rid of the fireflies/artifacts.
Rendered with Luxrender.
Ah yes, i've read that post, but from what i understand, it's strictly relative to Cycles, or does it apply to Luxrender too?
You are right, althought some of the measures could be applied also to Luxrender. Increasing the sampling rate, I.E., but I think you've considered this already. In any case, I like your render. Take care.
Very good. To eliminate the fireflies read this: http://www.blenderguru.com/articles/7-ways-get-rid-fireflies/#.U76zXaFMvVM. Hope it help.