So looks like I've opened up a fun discussion here, but I'll just say 
that the NSLU setup works great for me at my house.  Everyone is 
wireless (54Mbps) and all systems are able to connect to it at decent 
speeds and I run backup jobs on the systems to copy any modified files 
in specific directories to it nightly.  I love it.  And the best part of 
all is that it is running on a very small, totally quiet (ok the drive 
fan makes noise), and low power footprint box.  I really didn't want to 
have a huge box up and running to do the simple tasks I needed the box 
to do.  

So your mileage may vary, but to share files, have a central backup spot 
for pictures and small videos, and do other fun little things its 
great.  I do have other systems that require high speed data transfer 
but I'd never use any sort of NAS with them I'd make sure the data was 
on a local internal drive.

--j