I was in a similar situation and went m3 for 2 reasons:
-I had a very good deal at a local store (~800$ including type cover)
-No fan and slightly lighter
Performance wise I'm only interested in battery life as I use the tablet for similar things as you. Which is OK, better than expected. I was surprised to see that it can easily handle some slight gaming though I get about 4-5 hours of resident evil 4 for example. Pretty good when you hear the Nintendo switch will only do 3h.
Thank you so much for your input - I really appreciate it! xD I'm also pretty excited about the switch...