https://petersouter.xyz/fosdem-survival-guide/
https://blog.bytemark.co.uk/2015/09/07/my-guide-to-fosdem-eu...
It will be the first time at FOSDEM for me, so I cannot confirm or deny much, but I've definitely heard from multiple sources that it is very crowded. If want to attend a certain talk you absolutely have to arrive early.
I have not booked a hotel yet, so if you know a good place to stay, especially near the venue, pointers would be appreciated. My contacts are in my profile.
Finally a shoutout to the Rust crowd, links to the track and the Dev Room: