Ok, so anyone asking this question needs to realize that nobody here can really answer this question for you. Everybody has different sized hands and amount of flexibility in their hand/fingers. Plus, people have different comfort levels with how securely they want to be able to hold their phone while typing one handed or how far they are willing to stretch their finger to type. I'm not here to rip on people asking these questions, only looking to help them in getting a real and personalized answer so they are happy with their purchase. (I also don't want a bunch of people guessing and buying one of the few 6+'s available just to turn around and return them cause I want one real bad, haha)
The answer for those wanting a phone on launch day is go to your nearest Best Buy or carrier store and hold a Galaxy Note 3 in your hand, type with it, surf the web with it, just experience it. Ignore that it's android and it doesn't have reachability, just see if you feel comfortable holding and using a phone that size. I know the size isn't exactly the same, the iPhone 6+ is narrower but taller and thinner. My point is, if you can hold a Galaxy Note 3 and feel comfortable with it's size and your ability to type one handed then you will be perfectly fine with the 6+ as it will be narrower. If you aren't comfortable with the Note 3 then you probably should be going with the iPhone 6. I did this just this afternoon and cemented in my mind that the 6+ is for me, I was surprised how easy it was to type one handed on the Note 3, and with the 6+ being narrower I know I will be fine.
I know this isn't a fool proof plan, but it makes more sense than asking a bunch of random people on a internet forum something they can't really answer for you. Just my 2 cents, hope it helps.
The answer for those wanting a phone on launch day is go to your nearest Best Buy or carrier store and hold a Galaxy Note 3 in your hand, type with it, surf the web with it, just experience it. Ignore that it's android and it doesn't have reachability, just see if you feel comfortable holding and using a phone that size. I know the size isn't exactly the same, the iPhone 6+ is narrower but taller and thinner. My point is, if you can hold a Galaxy Note 3 and feel comfortable with it's size and your ability to type one handed then you will be perfectly fine with the 6+ as it will be narrower. If you aren't comfortable with the Note 3 then you probably should be going with the iPhone 6. I did this just this afternoon and cemented in my mind that the 6+ is for me, I was surprised how easy it was to type one handed on the Note 3, and with the 6+ being narrower I know I will be fine.
I know this isn't a fool proof plan, but it makes more sense than asking a bunch of random people on a internet forum something they can't really answer for you. Just my 2 cents, hope it helps.