My kids and I spent a couple hours in one of Powell's smaller branches last weekend. My 11yo hadn't been before and was completely enthralled. My 14yo has been to the main location so was much less impressed.
I like stores like Powell's for finding things that the echo chambers I frequent on the internet don't list. They've got a lot of staff picks that I wouldn't see otherwise. I sorta feel bad that I won't buy anything from them for myself though, ebooks only for me, although my girls each ended up with a handful. Instead I picked up a couple trinkets and games to show my support.