I should've been at the NY one today, had the RSVP to #YouTubeBlack but my travel plans got delayed. :-(
I've heard great things. Seems to vary by location. I know the NY one needs 1K subs for attending the workshops/meetups, then 10K for using the equipment (with varying degrees of how many times you can in a month depending on how many more subs). This thread summed up a visit to the NY location-sounds awesome: yttalk.com/threads/youtube-spaces-build-your-channel.208243/#post-1890032
Mildly annoying fact: It used to be 5K to use the space here, figures when I finally hit that milestone they change it to 10K.

I hope they don't change to 100K whenever I finally get 10..