Heh, whenever I hear "calibrate the screen" I assume you either work at an Apple Store or have been to one recently, as that seems to be their favorite line.

Calibration is only necessary on a glass-only repair; it realigns the digitizer "touch web" with the top glass that you're actually touching. That's why we don't perform nor recommend glass-only repairs.

When we repair a screen, we test every part of the digitizer before giving it back to the customer. We type on the keyboard, open apps, etc. If we find a dead spot, we replace it on-site. If by chance there's something we missed on our test, that's why our warranty exists.

If a customer finds a dead spot or the digitizer starts glitching, that's covered under our warranty. And that's why I recommend you find a shop with a good warranty. Most of them don't test as thoroughly as we do, but even with testing, a small percentage of digitizers will still have issues a few days to a few weeks after the repair. A warranty will get you a no-hassle replacement as long as you haven't cracked the screen.

I meant color calibration. I don't work for Apple. I had a non-Apple iPhone 4 screen replacement and the colors were washed out, lacking saturation - it's impossible for me to say whether that is due to display quality or lack of calibration. However it makes sense to me that color calibration is required for consistent display performance especially when displays are sourced from different manufacturers.