can you define radio exactly im not a phone expert and ive been having some rough signal issues also just at my house and neighborhood...im in the greater boston area..whats worse is if i got about a mile up the street i get 4 bars
No prob! So radio firmware controls basic low-level functions like network connectivity, Wi-Fi, and GPS. For several years, though, "radio" means "baseband", and controls network connectivity aspects only, while WiFi and GPS are governed by OS drivers, like any other devices.
Usually upgrading your radio won't give you any new features but will fix connectivity issues, increase range or performance, decrease battery usage, or the like. Some ROM's require you to have the latest radio versions to work.
A botched radio upgrade can brick your phone, the process is basically the same as upgrading your ROM. Just make sure not to unplug or power down your phone in the middle, make sure you trust the person who released the radio firmware, and try to read some comments or reviews.
I have updated and tried different radios, and have found that the one I currently use gives me a bar or two when my wife won't have any, etc. It just all depends on the radio, where you are at, etc.
BUT! It works both ways. You might go to a different radio and find that you have worse service with it. You just gotta find what is best for you.