I usually don't do anything half-way. Granted, I may never use the 64 to its potential but that's just how I roll. I'm sure my son will thank me later when I get tired of it or trade up to the 3GS or whatever follows.
I sometimes wish I'd payed the extra for the 3G but I'd heard so much bad press for expense I gave it a miss, I decided on the 64gb wifi model. Impressed deffo, and when it's jail broken I'll try tethering it!!