Samsung Galaxy Note II storage question


I am pretty confident at this point I'll be picking up a Samsung Galaxy Note 2 once it hits the market (presuming it's not banned off the face of the Earth by Apple first, somehow), but I have a question, and, I'm not entirely clear on something:

The Note II comes in three variants, 16 GB, 32 GB and 64 GB. However, what's the point of buying anything other than the 16 GB (maybe 32 GB) if it supports up to 64 GB via micro SDHC? Plus, to my understanding you can install apps directly to the MSDHC as well? I presume this is due to local caching, performance, etc. which is why you would want to use local storage only, but, to that, I ask: if you buy the 64 GB, is there really enough of a reason to require it? The app store just doesn't provide enough interest to need it for apps themselves, music and video can put dumped in the much cheaper MSDHC instead; so why buy the higher storage capacity? I know this is a very subjective thing, so, it's a bit of preference involved, but, I'm curious to know what the leading factors are, so when the time comes to pay the premium I'll know for sure what I'll be picking up internal-storage wise.

Anyone who wants to clear this up for me, please, do, I'm sure I'm missing something fundamental here.