Not to knock the enthusiasm or kill the mood, but you better know that going to a phone of that size and length will completely catch you off guard and likely irritate you since you were used to the 3.5 form factor.
I might suggest checking out both models in person. The 6 is far more capable of being a one-handed device akin to what you were used to at significant screen size increase. But if you don't want that, then by all means go towards the Plus. Just keep in mind that you'll have to completely change how you use or qualify as a "phone" in terms of the compromised portability.