Re: i have a choice of saving contacts to device or to SIM card. Which should I choose?
Contacts really should be saved to your Google account for automatic backup and easy restoration or transfer to a new device. Foolproof and super simple.
If you save contacts only to the phone just be sure to do manual backups and keep a copy somewhere other than on the phone in case of theft or loss of the phone.
The option to save contacts to SIM cards is disappearing and no doubt will be gone completely in a year or two. Unlike other contacts options, SIM contacts can have names and numbers only - no email addresses, physical addresses, photos, birthdays, notes - none of the extra information most people like to be able to add. In short, SIM contacts is old, outdated technology that should not be considered a viable option.
All that said, again I *highly* recommend saving contacts to your Google account.
Android user since v1.0. Linux user since 2001.