7MB/s is pretty slow by today's standards though. Most of my CF cards for my pair of D800E's are 30, 45, 90MB/s write.
A CF card is also physically a lot bigger than a microSD card, allowing the card's controller to stripe data across multiple flash chips the same way an SSD's controller does.
To a photographer nothing is worse and more distracting than a camera that doesn't go click when you push the shutter release!
I'm not familiar with DSLR cameras, the ones big enough to take a CF card instead of an SD card. Do they play a note after each shot whose pitch gives the photographer an idea of how full the buffer is?