Shouldn't it be faster to transfer files to an iPhone using the new Thunderbolt 3/USB-C to lightening cable in iTunes on the new 2017 iMacs? I tried transferring 1.24 GB music from both the TB3 port as well as the regular USB port. And both took approx. 47 seconds to do the transfer. Is USB 3 as fast when it comes to file transfers or am I missing something? I thought the TB3 would be faster. I'm using the USB-C to lightening cable from Apple, that I'm also charging my iPad pros with.