Had this phone for nearly a year now. This phone did not suit me at all. It was awful.
Battery Life terrible - I get 18-24hrs on medium to heavy use
Crashes a lot - Only on certain apps which I either get rid or wait for updated version e.g. Skype
Too many bugs - WP8 OS have bugs like all software but none that I noticed, occasionally the BBC News app crash on me when I multi-task, but that App is no longer supported, I managed to keep it since getting it back in WP7.5
Lack of any multitasking - Apps dependent, all my most use apps no longer do this 'resuming' business.
Horrible for typing - Subjective, coming from an Android and BB user, I'm fine with it after 2 weeks of 'getting used to it'.
Lack of any top apps or good games - Lack of Kairosoft games is the only down for me, plenty of decent Xbox and indie games to keep me occupied between working and using 'top apps' such as Metrotube, Weave (one of the better RSS/Newsfeed reader) e.t.c.
What's App - now improved but still terrible riddled with bugs. - It works, it's functional and no problem for me, including notification when receiving messages, many complained about it, not happened to me.
Skype? A company owned by MS but have a useless app. - Totally agreed.
No Instagram - 6Tag and the likes, don't see an issue with "no instagram".