I can fully understand the logic for 32, and would even go so far as to recommend 32Gb for most people. I am lucky enough to have great coverage, several external batteries, and unlimited data, so I went with 16Gb. For music and Podcasts, I stream everything, when traveling, entertainment media goes on one of several tablets, not my phone, and I only use a few games at a time, so even 2 big games won't fill it up for me. On the other hand, if you like pictures, video, lots of games, and want local access, 32 is the safe bet, and possibly some form of external storage as well (they have those USB flash drives now with a full size plug on one side, and a micro plug on the other). These devices are also part of the reason why I am confident with the 16Gb, as if I do find I need more storage, I can easily get one of these drives, and it is easier, faster, and cheaper to replace/get more of them for further on-hand storage.
IMO, it boils down to what are you using now, and how much storage are you using, and do you see your use case changing?