5310 all the way... Still getting customers that STILL have this phone in working condition. VERY thin phone. Feels like you will break it, but unless you are trying not many have.

5130 is actually the newer phone dispite the number sequence, nokia odd system for models. It does have a louder speaker and feels more durable.

Both have buit-in fm radio. Micro SD and a camera. Both will have simial reception patterns.

Exquinox is not a popular phone, it seeems to drop calls for us here in MN.

RAZR my be a step too far back.