uIntelliSense brings all the power of IntelliSense code hints to your Unity code.
Have you ever forgot the exact meaning of some method parameter, or stumbled upon a method you’ve never used before? This is what uIntelliSense is about, providing useful hints for the Unity API — descriptions for types, variables, methods, method parameters etc. Don’t you think that searching through Scripting Reference is way too much work when all you really have to do is to hover over the code with your mouse?..
Once you’ll try it, you’ll get used to it immediately. It is extremely helpful and time-saving, especially if you are a beginner who doesn’t knows the Unity API very well.