I suppose if you don't mind paying double (or more) for the same thing it's fine.
A new 120GB SSD is under $100 and a portable enclosure for it is about $20 or so. That has no moving parts, consumes near-zero power and is a general-purpose storage device. It also works great and is MUCH faster than the head unit will ever be.
Cheapest price on iPod 160 gb on ebay 249.00, intel 320 series 600 gb on ebay 259.00 or best offer. tickerguy is spot on. My opinion about storage units for mobile use takes into account these things.
1. first of all reliability, a spinning hard drive, needs to be kept as stable as possible while it is in operation, bouncing around in my console or glove compartment would kill it. this is why ssd's are geared towards laptops more than anything. hence their size 2.5.
2. power consumption,
3. speed, not so much in this case, head unit reading at usb speed, not sata III.
4. price per gb, in this case more comparing ssd to iPod. since hdd is not an option for me.
Tracks sort correctly assuming they have numbers starting their filenames if you use the folder view.
What breaks in THAT situation is the folder name sort (and at the top level artist sort), which is just plain fooking stupid.
It's particularly stupid because we know there's a quicksort (or similar) call in the code at the FILE level, since it plays the tracks in order if you're in folder mode! Therefore, one call to the same thing when displaying the FOLDER list and....
Yeah, it's that dumb. That's one of the reasons I want (badly!) a dump of the firmware and the ability to load updates. If I have to I will disassemble and hand-patch the disassembled .SMALI code to fix that.
Whoever is the programmer responsible for that at Pioneer ought to be deep-sixed on a permanent basis in the programming community.
I love all the options we have to add storage for this thing. I myself however just use itunes match ($30 a year) and my iphone. All 20,000+ songs right there whenever I need them without taking up space on my phone.
Unless you don't have an internet connect then you have no music 
I'm constantly connected to LTE. It also caches as much music as you have room for. So technically I have around 3000 songs on my phone. They just delete if the phone needs room.
I like road trips -- including in places where there is no cell service, or where it drops back to "stupid slow".... 
Unless you don't have an internet connect then you have no music
Haha. True. I don't pay. I use google play and upload my whole media library from iTunes there and it works great on the NEX. Upto 20k songs free. Not a dime.