The Showbox is a quality live music venue with some of the biggest names on the bills.
There is a lot to be happy with about the Showbox. It is very open and large, there are multiple bars and the security is USUALLY very helpful and unobtrusive.
There are also a couple of OKAY things about the Showbox, as mentioned before it is a large room, so unless there is a good number of people filling the floor the acoustics tend to be less than desirable. They have a massive 44,000 watt system that had problems with empty rooms. So if you intend to see a show here it will sound best if you choose to go to a show that is sold out or close to sold out.
For the bands, the Showbox has a strong lighting system, solid sound system all the way around and is easy to load into and out of. They have great hospitality areas in the back by the Men's room with a private men's and women's bathrooms, two private green rooms and even a private lounge area. There are also multiple exits and entrances so you can slip out away from waiting crowds to your bus.
Overall the Showbox is one of the best venues in Seattle, it is also one of the biggest. This is a great place to catch a national act with a large crowd. If you want to catch a local act try the Crocodile, The Central or El Corazon.