Phone: Samsung Exhibit II 4G (unlocked)
Bands: GSM Quadband; 850/900/1800/1900MHz UMTS Tri-band:1700/1200, 1900, 850MHz
AT&T uses 850/1900
TMobile uses 1700/2100
Tether: Wifi hotspot
Laptop: IBM T60
MVNO: Net10 BYOD $45 Unlimited
Roaming: TMO sim would not roam on voice or data while the ATT sim had coverage.
Feedback: At&t has the better coverage but T-Mobile has the faster network. Net10 also has a Verizon phone but GSM just sounds better to me; for now I'll be using the net10 At&t sim.