I've been researching the display calibration device called Spyder. I notice that the more expensive models have ambient light settings. This seems to be the main exclusive feature when it comes to the higher priced models.

Is the lighting of your room really going to make that drastic of a difference on what you see on your screen?

Is there is a basic recommended lighting environment for color correcting?

Does the Spyder properly adjust your brightness level? ...this probably correlates with how bright your room is.

Lastly, is there really any right or wrong way to color correct?

All these variables and options are driving me nuts!