Just look in this entire sub forum, if you like a specific way someones phone looks (custom ROM) you can change it, if you would like to change your OS version (leak or revert) you can change it, if you would like to remove the apps that Verizon pushes onto the phone (which you cannot normally remove), you can remove them, if you want to change the smallest detail of your phone to make it "your" phone, you can change it, if you want to change (modify) the hardware settings like over clock, under voltage, you can change it.
Basically, stock Android is great, most of the time stable if managed correctly but still limited to what you can change and/or modify. Un-rooted phones can still accept launchers, which do change the appearance and functionality but they still sit atop Motorola's factory build and framework. Rooting lets you access and modify files beyond what Motorola stock is set us as. A simple way to explain is, say on a normal windows PC you can only access "documents" folders and up, rooting would allow you to read/write all files/folders down to your "C:\" drive, and also show you files/folders that are normally "hidden" for system usage.
There are consequences to rooting though, if you create them. If you root, read everything you can about the subject, take your time, if you don't understand a term or method ASK, or SEARCH about the subject. Don't rush into methods, research them, sometimes there are easier ways to apply changes but if done incorrectly it will brick your phone. There are ways out of such problems though, and the people here will be glad to help you out of the woods if such problem arises.
It does VOID your warranty if you return your phone rooted, but in most cases you can remove root and restore back to factory state.
I've taken my time, learned everything I could, asked questions, stumbled a few times but knock on wood, no brick, no boot loop yet - everything has gone smoothly.
Just take your time, experiment within your knowledge, and best of all - make YOUR phone YOUR phone, not just another Droid X
