Did you see the link in my post with what Legere said? T-Mobile Help/T-Force confirmed i5 but with Legere saying it, that's final word.
You're copping JOD, EIP, or full price? EIP, that's a $429.99 Down Payment plus taxes. That's under $540 total. Your $600 would cover that. 256GB X. 8+ is $200 less in DP. $316 total. $316 to $540? That's a big fukking jump, but if you got it, you got it. Follow your heart. My Jailbreak 6+ has been feeling it for a while, and I'm still on iOS 8. I'm upgrading but to what, I don't know. Touch ID might be the reason I'll pick 8+ or Note 8. That and X size is smaller than the Plus, so everything is compact now.