Well it depends on area. They are showing they can outperform the others in some markets but have not completed the rollout.
Sprint is showing better performance in their home market...
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I use over 10GB/month and get 6-20Mbps consistently, up to 30. The new triband network can 60+. When they get 800mhz out more broadly, they'll compete better with ATT/VZW on coverage. Overall I wouldn't recommend Sprint until they complete the rollout.