Have a GCI prepaid phone I activate for rural Alaska trips. Even in Anchorage, pre-trip, data sucks balls. EDGE and 3G, both spotty, outside Anchorage. Text and voice phone calls were the only reliable things in all locations.

On the road system, ATT is far superior to GCI. GCI's only benefit is that in rural Alaska communities, they're the only presence. If you're headed into the backcountry, no one has service, unless it's near the TAPS right of way.