The Netbook with Bluetooth was awesome, but even with a 5 amp/hour battery I had in mine, the battery life wasn't great while listening to music. It had a power hungry, motor-driven hard drive and an earlier version of Bluetooth, which it definitely wasn't optimized for.
So, the Netbook didn't seem to work out for music duties, or to be a Windows machine in a pinch, which it was a little under-powered for. I ended up with the soccer mom mobile office configuration, which is a powerful laptop and a 10 inch, dual core 32 GB Acer Iconia Android tablet, running Ice Cream Sandwich. It also has a 32 GB micro SD card, bringing its total storage up to 64 GB.
The Android tablet with its powerful but efficient Bluetooth radio has turned into the dream music player for me. Both the tablet and the headphones will go all day on a charge. What I like about this particular tablet is that it has a standard USB 2 port, which can even accept a USB hub for multiple devices. I can put music or movies on it from a flash drive, and it'll even spin up my portable 1 TB drive on battery power. It can also connect to the network, though it doesn't have the best WiFi radio and the file transfer speeds aren't that hot.
None of the apps I tried at first fit the way I organized music, which was putting my albums and play lists into a neatly organized file folder structure. But I found a folder player app which does everything I need. Now I can jam a whole bunch of new music onto the tablet, hit shuffle and go all day. It lets me keep my music organized for all my devices the same way.
My Motorola over-the-ear headphones work much better with the tablet than they did with the Netbook. I get really good range and the convenience of the media player controls too. It's a dream setup for music. It's pretty good for movies, too. The hardware acceleration works flawlessly for both audio and video most of the time. Right now I have my Band of Brothers box set on it. Tom Hanks + Steven Spielberg + Android + Bluetooth = 10 hours of awesome.
It's hard to imagine a better setup. More storage, better range, better battery life, sure. But pairing an open software platform with a mature hardware platform is a nice start. Rock solid reliability, and I don't get the impression that Google cares about how I listen to music. I'm a believer.
It's a good setup for streaming music too. I listen to a few Internet radio stations with the WinAmp app, and of course it's great for YouTube.