I will give you my experience. I have all old Kilfer pull disks. (John Deere bought them out looooong ago) 6', 8', & 12', all had smooth blades when purchased. Now understand that the ground that I was disking for the first time was burned in 2002 from The Pines Fire. All of our land was covered in 6' - 10' tall brush, sage, and scrub oak. Lots of branches and limbs between 1" & 4". When I started on the disking I was using the 8' disk with smooth blades. One of the biggest problems was that the disks would get hung up on the branches and stop turning, thus becoming a 20 bottom plow.

Have you ever tried to pull a 20 bottom plow,

you don't go very far.

Anyway constantly had to stop to get the disk unjammed, or get it to hop over a 4" branch. Ended up re-building the disk and used 3/16" notched blades 22" tall. Now the disk hops over branches almost all the time and you can tell at a glance that the disk is turning. Before with the smooth disks, sometimes when they were jambed up, you couldn't really tell until you were stopped from that 20 bottom plow.
I think that the smooth disks work good in ground that has been disked before and does not have all that much vegetation to be turned over. The notched disks work better for hard dirt and ground that has a lot of vegetation that you want turned under. Myself, I would only get notched disks. When I rebuilt my 12' disk, I used all notched disk blades. If you are disking bigger vegetation, notched blades are the only way to go.
Just my opinion, based on my experience, others will vary.

Here's a picture of my tractor and 8' disk, before I quit for the day.