Just realized he/she meant "after-show", not aftershock!!!
I vaguely remember aftershock from my teens being a nasty herbal/cinnamon liqueur. A poor man's Goldschläger!
Anyway, the crowd was fine on the night I went last year. I went to the "Ego" night, so your mileage may vary. There were some mature (50s & 60s) people there, mostly for the show, but I would bet that the average age was about 40, single women typically younger than men . Everyone attractive, well dressed and behaved.
"Grown and sexy", as we say in the states.
People were dancing and were generally up for it. The show ends at about midnight and the place goes full-club. Most of the dinner crowd was gone by 2am or so. They shut off sections as the crowd dwindles so it stays crowded but gets more intimate. I was gone by 4am, but that is because I cant sleep-in and that overrode my curiosity.
I like the venue, music and people so I will probably be back, and I like Felix. Hope they sell they tix on here this year. Last year, I had to use ticketmaster.
Last time I saw Felix the Housecat was on the Mysteryland festival in The Netherlands. Think he was playing in the Subliminal Sessions tent and Miss Kittin was with him to do a live Silverscreen.....crowd went wild. Might check it out, since I got no plans for Thursdays yet.