Although the model number, 640, is lower than the older flagship/almost flagship numbers like 925, by feature it is at least as good as the 925, possibly the worst phone Nokia ever made. (I've had three different IMEI's and even after five? trips to Customer We-Don't-Care, none of them connect reliably. Sometimes not even with the TMO booster 15 feet away!)
The 640 is loaded with features at the old 521 type pricing. I don't need/want a 43mp camera, a giant screen, or a processor speed that I'll never use. What we do get with the 640, besides an astoundingly low price, is a flash, removable microSD and battery (again, another issue with the 925), three 700mhz LTE bands and HD voice, WFC, FM radio, and lots of bluetooth types.
It's as much "flagship" as I need. YMMV, but then I don't have much ego and think that I don't need whatever is newer or allegedly "best."
The MetroPCS 640 page is up for pre-registration, wasn't there a few days ago. On the official MS 640 page, buried in the footnotes, it mentions, Cricket, TMO, and Metro by name. I wonder why ATT is bypassing this model?