differences.. Sprint was acquiring a better "BRAND" Nextel was at the top of their game for the push to talk & corporate markets which they served.. Then Sprint took a huge dump on those customers and lost them to Verizon.
Metro PCS? Very small geography coverage (for data) coverage and barely tolerable prices & terms of service. The good? From time to time they throw out cheap phones and plans which are "limited time offer" such as the $25 a month unlimited talk/text/web plans.. This is a deal where spectrum synergies come into plan jettisoning CDMA for GSM. Tmobile is in the best position to take AT&T customers rather than Sprint's upfront (which I thought the other way around-- at least not yet, until LTE becomes universal for voice & data).
Tmobile wants to be assoicated with that kind of aggressive customer grabbing marketing... albeit not at such low prices.. So, time will tell whether this deal is a substantially good one for consumers.