At first I was a little upset when I heard the gs6 and edge would not get SD cards and started reading up on what they got inside that sucker. Samsung has been criticized for having laggy TouchWiz and did this to help rid of any lag on the device. The new memory is using universal flash 2.0 and runs on a sata 300+mb/second scsi type connection and is using the same tech in the fastest servers using in same fast harddrives.this type of setup is 3× to 4× faster then the fastest SD cards and runs on a completely different system bus type. If they would add an SD card and people started putting huge movie files and system games on it there would of been a huge cluster **** bottle neck and the system would lag and run like crap going back and forth trying to read from the SD card. Think of it like having an old ide mechanical hard drive installed on a computer with the fastest ssd drive and loading the os and huge files on the old ide standard mechanical drive vs the sata ssd drive. They had to ditch the SD cards to make it all work right.