I'd actually be comfortable claiming that everyone's slow iPhones are actually faulty. Because mine (5S) was really slow and not even a clean reinstall would he

I'd actually be comfortable claiming that everyone's slow iPhones are actually faulty. Because mine (5S) was really slow and not even a clean reinstall would help, and I went to the support service for my carrier and they sent it for service and after a few days sent back a new iPhone because the old one was broken. The new one was much faster even thought it was the same model, and had the same OS version. So, people, get it checked out, it might be faulty, for example the NAND flash memory might wear out or the base firmware might've been corrupted, or hey, the battery might be bad...