I don't think it is, but I like to keep a lot of media and apps on my devices. I have a 32GB iPhone, and it doesn't seem like enough to me.
If you plan on doing activities that mostly involve streaming media or remote access, you're probably fine with 16GB. I don't think ebooks will take up much room, so that won't make a big hit either. But if you're going to drop your entire iPhoto library and a bunch of movies on there, you might want to upgrade.
If you plan on doing activities that mostly involve streaming media or remote access, you're probably fine with 16GB. I don't think ebooks will take up much room, so that won't make a big hit either. But if you're going to drop your entire iPhoto library and a bunch of movies on there, you might want to upgrade.