Best prepaid offering for Mexico?

[RTuesday]

Originally Posted by petkow

Big oops. I just had a look at the Telcel website and it looks like there is no Telcel coverage in her town (Ixtapa which is in Guerrero State). Might have to check the Movistar route after all.

Strange it's not listed even under Zihuatanejo but the local expats there seem to use Telcel:
Phoning local information - Ixtapa Zihuatanejo -

The GSM world maps are a bit lacking in placenames but it should be around here:
GSM Coverage Maps | Mexico | Radiomovil Dipsa SA de CV (TELCEL) (TELCEL GSM) | Coverage Map