yesterday i was getting network errors for texts and my phone kept "prepairing network", idk whether or not it had to do with the fact that i rooted it, so i sent sprint an email, and unrooted (just incase), sprint replied with the usual bs, we are constantly upgrading our towers to bring you faster speeds, if you encounter any more issues with services bring your device in for inspection.
after unrooting it went away though.... after 3-4 updates
so maybe your towers are actually getting worked on?