Eh...this is a good and bad thing.
It's called OTA (over the air) updating. They use it for pretty much everything now-a-days, for actually programming the phone (getting the number into it, and the home NAM and SID--system ID stuff). This is what would update if your phone number or area code were to change.
They also use it to update PRL (Preferred Roaming Lists), basically, it tells the phone what towers to look for, and in what order. So yes, your digital service may improve if you do this update.
It IS NOT a firmware upgrade! Those have to be taken into the store to get done. Some phones have had several firmware upgrades. With sprint, it's best to call to make sure they have the equipment for your phone, go into a store, hand it to them and tell them you want to make sure you have the latest PRL and firmware. They should be able to tell you, or have it done within 5 minutes or so.
Verizon Customers...
It's almost ALWAYS best to go into the store and have them do the *228 upgrade. In Ohio (former Airtouch region), the *228 programming was inputting the NAM and SID's backwards, at least through September of 2001. However, it would strangely work fine in the home area, but when travelling, things would become difficult.
Clueless reps or alternative sales people (radio shack, etc.) just used and assumed the *228 automatically inputted the correct information, which would actually degrade your service if you were travelling.
