Lots of apps - some of my most-used apps are space-hogs (not even games, really). The rest is photos, movies, music, nandroid backups, titanium backups, etc. I mean, I can live with 16GB, but in 2012 (almost 2013), 16GB as a max is just kinda limiting. The lack of LTE doesn't bother me - I'm on StraightTalk, so I don't get LTE anyways.
Have you touched a Nexus 4? I'm also somewhat concerned with the build quality, based on previous experiences with LG products.
Lastly, I may give it a month after launch to see if there will be another version, a la Nexus 7.