Initially I had doubts about the 6 Plus. I've always been the person that said I wouldn't be interested in Note sized gadgets.
Still, I ordered a Plus sight unseen, because my 5s with the Lifeproof case was as big as a regular 6. I felt like a 6 didn't offer enough upgrades to make it worth it. Battery life has reportedly been about the same, etc.
I didn't even go into the store to hold them yesterday when I arrived; I just went straight into the reservation line.
When my turn came up, the guy asked if I had held both phones yet and that most people end up preferring the 6 Plus. I said no, so as he got someone to bring out my phone, we went over to the display where I got to hold both phones for the first time. I'm not tall, about 5'9" but my hands are big enough where I felt completely at ease with the Plus.
Of course, I am one subjective anecdote. Your mileage may very.