I agree 100%. For me, there is a point where I have to use a phone two handed. If I have to do that then why not get the largest one I'm comfortable with; which would be the 6 plus?Same for me.
I wasn't ready for the Plus last fall, it was a huge difference from the iPhone 5 so I went for the 6 without hesitations.
After a few months the Plus still feel "big" but I might give it a chance next time. I sometimes have problem controlling my iPhone 6 with one hand, so if I have to use both hands for the phone why not buying the 5.5'' model with a lot more real estate on the screen?
If they'll put multitasking on the Plus only they'll help me make my decision