It can't give full coverage, and it might be a shoddy experience for a while, depending on where you live.
For 3G, it can only connect to T-Mobile's 1900 MHz band for 21 Mbps HSPA. This should still cover most areas, but T-Mobile's AWS band is more widespread and is capable of 42 Mbps.
For 4G, it can only connect to T-Mobile's 700 and 1900 MHz bands which just started rolling out and will take a while to complete. T-Mobile's main nationwide LTE band is on AWS, which the Dev edition also doesn't have an antenna for on LTE.
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