No Sprint has continueto lose customers long before Sprint closed Nextel. They didn't shut down Nextel until they were purchased by Softbank. Don't look at 6 months with gimmick plans and lock ins in the near future their numbers will go down when contracts and payment plans expire. Just like T-Mobile will happen to as they won't be able to expand their network fast enough to lose a lot of these customers.
Yes I am a T-Mobile, ex Sprint, AT&T, and Verizon customers.