To save a few keystrokes you don't need to type

Print MyVar

to see the value of MyVar. You can just do

?MyVar

Besides printing and changing your variables you can also temporarily change the location and/or size of controls and/or your form. This can be useful if say you are designing a form and you want to move some control a little bit but you don't know exactly how much. In the Immediate Window you can type MyControl.Left = 1234 or MyControl.Left = 1245, etc until you have it exactly right, and once you have the value you can change MyControl's Left property in the IDE. That's a lot faster than doing it over and over in the IDE directly.

BTW some uses of the Immediate Window are discussed in my VB6 Debug Tutorial.