My mistake...missed that part when I was reading through.
I've definitely got some good memories from the Sonar, saw some great bands there for sure, but I can't say I really miss it as a venue. Always thought the sound in there was hit or miss, depending on which side of the stage you were on, and goddamn could it get hotter than hell inside if you weren't standing directly under one of like, only three A/C vents in the building.
Was it bankruptcy that got them? I know the majority owner got nailed with a 10 year prison sentence for running some kind of illegal drug ring, but i never heard exactly why it got closed down.