I went to the Apple Store last Thursday and heres how my visit went.
Before arriving I knew it did it most consistently when its cold. EG, every morning when I first pick it up you can click the bottom right corner repeatedly for about 10 minutes. Then as it warms up it seems to stop.
Luckily, last Thursday in Manchester was freezing, so I had my phone out as much as possible while my girlfriend was looking around Top Shop as we made our way to the Apple Store.
I arrived and explained my screen clicking issue to an employee, and my plan of making the phone cold worked. It was clicking, and I was relieved.
He agreed that it wasnt right and his friends iPhone 5 had the exact same issue, he took my details and told me to come back in an hour as they were so busy and they will replace it.
An hour later I arrived back, but because I was told I was getting a replacement I hadnt bothered keeping it cold and used it normally. When I got back to the Store it wasnt clicking nearly as much. If I left it on a table untouched for a few minutes you could make it happen.
I got sent to a genius to explain my problem, and I also told him another employee agreed the phone had a loose fitting screen and that getting a replacement wouldnt be an issue. But he couldnt make it click.
I looked around for the employee who had agreed that my phone was faulty, but he wasnt there anymore. I explained to the Genius that I travelled a long way to the store, and I wouldnt have bothered if the phone was fine, and if I cant get a replacement I will get a refund and order a new one if I had to.
He typed some more stuff into his iPad and disappeared out the back.
While he was there I put my iPhone into airplane mode and left it on the genius bar while I waited.
He came back with a replacement handset and began to unpack it. He said that if Im not happy with the phone, they would replace it.
I was really happy at this point, and he got out the replacement for me to check. It was solid as a rock and not a scuff in sight. Fantastic.
I could tell he wasnt delighted with giving me a replacement. So, with my old handset still on the table, untouched, I knew it would click, so I asked him to press down on the right bottom corner while its lying on the table.
Sure enough, it clicked, a click loud enough to hear from 5 feet away.
He was kind of shocked, and he said he could understand why I needed a replacement because he wouldnt be happy if his phone did that.
People may not think this problem is a big deal, but I cant explain how annoying it is when it happens every time you pick it up, or 50% of the time you hit the home button.
Theres a bit difference between rock solid, and not quite rock solid. And I think if you have this issue, and its bothering you, you should take it into the store.