Just about everyone I see with an iPhone has a case on their iPhone. With the Diamond Dog screen protector in place, there is just enough room to still support using cases.
The alignment was perfect, no bubbles were present, and the display is fully protected. My fingers slide easily around the glass and it has a great coating to reduce fingerprints.
The clarity of the display was also not impacted in any fashion so the lovely display of the iPhone remains. I never dropped my iPhone on the display to test its ability to resist damage. Diamond Dog states the protectors have been lab-tested to protect 3-6 times better against scratches, 5 times better against abrasion, and 3 times better against impact than leading competitor screen protectors.