Here's what you need to know: Do the self-guided audio tour! It's available in multiple languages,…read moreis free (they hold your passport or a $20 deposit), and completely enhances the experience at this museum. It's key.
Though it's about to begin an expansion, currently the Bauhaus-Archiv is a fairly small museum that I spent maybe 90 exploring. It has a spacious layout that (unfortunately?) doesn't strongly imply a starting or ending point of your exploration. As Bauhaus is a rather nebulous concept, the museum itself doesn't have one clear direction. There are a lot of interesting individual pieces, but without really diving into the concepts and history behind them, a cohesive picture remains elusive. Once again, GET THE AUDIO TOUR. It allows you to access most every item on display and go much more in-depth than the written signage allows. It really made my experience.
I found myself still wanting more, and when I inevitably return to Berlin in a few years, I'll look forward to exploring their expanded digs. But in the meantime, for any architecture/design/craft geek, a visit to Bauhaus-Archiv is quite worthwhile.
PS - The gift shop is spendy, and the cafe is tasty! A nice place to rest your feet.