They are among the most expensive of choices because they require specialty tools and specialty skilled labor.

Will they scratch and crack?

Joan:

Chipping remains a neary insurmountable problem with the printed porcelains as opposed to the through-bodies. To continue the pattern, the top must be mitered to build up an edge. The more rounded the edge, the less likely the chipping, but the more you round, the worst the edge looks because you're removing the print. When you do get a chip, it's very difficult to repair inconspicuously, especially compared to other surfaces.

Cracking is primarily due to fabricator/installer error. Do it the way Roberto Colonetti says and you'll be fine; he wrote the book.

Ty!

I too am wondering about this and found this thread to be interesting.

https://www.houzz.com/discussions/3980431/porcelain-slab-countertops#n=105