Personally, I had anticipated that 16 GB would be more than enough. I have zero interest in games, and memory was never a constraint on my Droid 3 (which had only 8 GB). I simply installed all my music, videos, photos, and other big files on the SD card.
But, GOOGLE is clearly not interested in promoting phones with external storage any more and music or movies from the playstore can't go on the SD card (at least not without using a PC as a go between, or rooting).
I am beyond the 14 day return period but I got my phone at COSTCO. I called them about an hour ago and they agreed to swap my phone for the 32GB model. The big problem now is that they also do not have that model in stock.