Avista.... 16 vs 32 vs 64 is dependent on how much content you intend to store on the iPad. Would you put all your digital photos there? All your music? I have mine set to not automatically synchronize all my music and photos from my main desktop....I select which ones.
I have over 150 apps, 400 songs, 1400 photos and still have only used 10 gb out of my original 32gb.
So, 16GB is probably enough for the average adult (a kid would load it up with all sorts of useless stuff). I went with 32gb for the extra cushion.
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Maryland (DC Suburbs) - first 51 years

The Villages - next 51 years