I have 5s 64gb with probably around 5000 photos on it. I'm plugging it to my 5K retina iMac with 32GB Ram, i7 4.0 and 512GB flash. After connection on some occasions when iPhoto is launched and I get the miniatures of all the photos on the phone it's extremely slow. If I scroll down say to the end of the whole library on the phone I have to wait for each miniature to load - sometimes its very fast I just scroll and the photos are there. Sometimes it's taking few seconds to load each one. I've been taking few photos just now, connected it to my mac, import, disconnect the cable take few more shots, plug it back in. I could get these slow speed connections three time in the row, and then when I plug out the phone after each time when I see that its slow I might get one fast connection. The cable is new, the phone is new, iMac is few months old. Is it the software, or iMac or iPhone ? Sometimes when it takes ages to load the miniatures I would not see my most recent photos - as if they weren't there.