The internal storage is just for the OS and apps, you put your music on a microSD. It works with up to 2TB.
I already have a microSD full of FLACs from my old Walkman A45 but the draw of this new one for me is I can also use lossless streaming from Apple Music on it and save albums I like without digging for FLACs.
If you're interested happy to do a lil review.
that is very neat, when you have option to plug in memory card. Never owned walkman, but I have heard only the good stuff about them. I just have my ancient iPod Classic. Might do an upgrade with this custom storage option, what I bought while back ago. 
I've got a modded out iPod with one of those things in it!
I even have the "5.5 gen" which has the best DAC.
Only problem is I use Linux so it's a bugger to actually put music into it.
Aren't there custom firmwares for those old iPods that let you use them without iTunes though?
I should look into it actually, I already own the hardware so why not?
