I'll get right to the point: the T-Mobile iPhone 6 (and 6 Plus) from Apple (not from a T-Mobile store) works fine on the Verizon network. Just eject the T-Mobile SIM that comes with it, insert your Verizon SIM, and boot. The T-Mobile iPhone from Apple appears to be entirely global, and fully carrier-unlocked, which makes it the best choice for those of us who like to buy phones outside of contracts.
I made this discovery after trying (and failing) for several weeks to buy a new iPhone 6 without a contract — something all parties involved make as difficult as possible. You can't order a Verizon, AT&T, or Sprint version without a contract; you can't reserve one online and go into a store to pick it up; Apple won't sell you a SIM-less, carrier-unlocked iPhone for the first few months after launch; and stores like Best Buy charge you $100 over retail if you want to pay the unsubsidized price (at least the one near my house).
But I eventually gathered enough information (and certainly plenty of misinformation) from enough stores and online sources to feel fairly confident that the unsubsidized T-Mobile iPhone 6 was not only carrier unlocked, but that it would work perfectly fine on Verizon’s CDMA and LTE networks. So I decided to take a chance and order one online.
And it works. I now have an iPhone 6 on Verizon, and a 2014 Moto X on AT&T, which makes me far more connected than anyone possibly needs to be, but allows me to indulge my phone fetish to the greatest extent possible.
Yes, an intervention is probably not far off.