anything better than dd to copy disk images to SD card in OS X?

I have used dd because it is what the tutorials suggest to do for instance when copying Linux images to SD cards (e.g. Raspbian, Kali, …).
This is done at 1 Mb/sec on my macbook pro. I have tried to change the bs option of dd, e.g. bs=1m or bs=10m or bs=100m but copying a 32 Gb image takes hours and the rate is always around 1 Mb/s.

I read on linux some users suggest to use cat instead of dd . This seems to not work for me as even with sudo I get an error for insufficient permissions.

Just to be clear, the disk partitions are unmounted via

sudo diskutil unmount /dev/disk2
sudo diskutil unmountDisk /dev/disk2

Also, I should have specified that dd works where cat is blocked by the permission error.

So my question is, what is the quick and reliable way to copy OS images of tens of Gbytes to a SD card in OS X?