In Reply to: They will work... but.. posted by benthomas on Thursday, 31. July 2014 at 13:44 Bali Time:
I have a locked Telstra phone, I take the Telstra sim out and put in a XL sim and it works fine. The simpati sim will not work in my locked Telstra phone.
Similar for Optus. The simpati will work in an Optus phone, so select your Indonesian provider. you can even send a text from Aust to Bali with the simpati sim and the message goes via optus in Aust.
Last visit in June the WIFI everywhere was very slow but free. Consider it like Australia. the nearest tower is 20km away the signal will be poor. tall buildings etc I found a little coffee shop in Melasti Street near legian st and signal was good on most days, and free.