To answer the question about detectability
Sprints method of control is call an NAI block. basically they have the manufacturer build in a method to switch to a second user name (eg.
username@modem.verizon.com). Which results in an authentication failure without the modem plan. The Titan and Apache for Sprint do not have this block. The only way Sprint can tell if you are using this device or the Apache as a modem is by usage. BUT, with peer to peer apps, torrent apps, and Orb and Slingbox for these devices, it is easy to argue that you transfer that amount of data legitimately with just the device.