Generally factory calibrated doesn't mean much. If you don't like the colors/brightness most people can simply calibrate it themselves to make things look good to them. But if you're doing photo editing and such then you'll want to get it properly calibrated if it's not living up to your needs.
Hi
calibrations can drift slightly over time so art monitors need recalibrating at intervals.
Also the printer should be calibrated or it may not match the monitor.