One interesting aspect of replacement is the difference between a good rework job and a bad rework job is typically environmental sealing. Does the case still snap perfectly tightly, with sealant/gaskets, if any, around the borders etc?

This is useful advice not just for people doing it themselves, but to evaluate a shops ability to do rework. If its a busy shop catch a guy leaving with a replacement and ask to see some completed work.

There is an analogy with programming where a mere "it compiled" is not exactly the pinnacle of all possible compliments.