I purchased both a 6 (for the wife) and 6+ (me).
Having used both now for 24 hours I think for me quite clearly I am returning the 6+ and ordering a 6 64GB.
The reasons for this are:
1. Its massive. I doubt anyone can use it constructively for any purpose with one hand.
2. Yes it fits in a pocket, but it is still huge and when you put it to your face to have a 'phone' conversation you look like a total muppet (sorry didn't really want to sugar coat it)!
3. The screen on the 6 is not significantly different to the plus (yes the plus screen is gorgeous but in my eyes doesn't justify lugging it around).
4. The battery on the plus is epic but the 6 is significantly better than my 5 so I guess even if I have to charge it once during the day, no big deal.
5. Games on the 6 plus actually seem to struggle with the screen. There was noticeable lag in Asphalt 8 for example. I am sure they will get better with time.
I am returning despite the better half telling me that I should get the 6 (not the plus) before I ordered. So I am not going to hear the end of that! That should tell you something about the scale of the decision!