On the wii u you can use External drives of any size as long as it is SD Cards, and USB Drives up to 2 TB.
a simple 20$ gets you the same storage space as the wii u deluxe
for 40$ more you never have to worry about HDD space ever again
I don't like sony's small HDD drives they include in their consoles, but i don't bitch about it, i just upgrade because sony allows you to upgrade the HDD (Except in the new Super slim models that are outside the US.)
Xbox 360's base Console is 4 GBs.
Sony's is 16 GB (super slim has a 16 GB SSD in some countries.)
Wii U Basic is 8Gbs. Right in the middle.
Wii U's Deluxe has 32 gb.
your average person isn't going to be downloading massive amounts of gaming content on their console. they mainly buy disc games and nothing else.