Gearhead wrote:
What ahem, I didn't say it did not exist? I just tried to point out why they're rare... ☹
It's an expense issue. Many builders of custom flat tops, and even some mass producers such as Martin will provide a slot head - for a fee. There is rather more work involved. A slot head can certainly take the strain of steel strings.
There are some folks that say that the slot head sounds better. This is to do with the angle at which the strings break over the nut (and possibly due to the vibration of the head).