No not if the unlocked device is branded to a different carrier.
just went through this myself with a Telus storm. Even though it was unlocked Bell couldn't activate it on their network. You will be able to use it on a GSM network though.
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Sprint has horrible customer service anyway.
I used to be a Sprint customer, and I would dread any time I would have to call them. After sitting on hold for 30+ minutes average, I would end up getting transferred around different departments in a circle, start all of it over again, and then get told that its MY problem.