I just found this post now. I was there, 3000 years ago (oh I mean last weekend, I live 2 hours of public transport away from Brussels). Had fun! Great talks, bad ventilation, had some beers with some people I only knew from a Matrix channel associated with a podcast (that was a very nice experience). Went to Bytenight, felt a bit out of place in the Offdem crowd but enjoyed it, met some colleagues, had one of the best waffles ever. Spoke to some bioinformaticians using Nix and we set up a Matrix room to coordinate talks (or some activity) for next year.
Will be going again next year, I highly recommend it if, like me, you have 0 friends that ever installed Linux or know what the GPL is. You are among peers.