I've personally attended two conferences and watched (portions of) two on livestream + IRC. If you've never been and haven't yet registered, I can't emphasize strongly enough how much more fun and rewarding it is to be there in person. If you've got the time and the means, just do it!
The registration deadline for DConf 2017 is just around the corner (this Sunday). As a fun way to remind you, a handful of past attendees have shared some anecdotes of their experiences.