the new dish (especially the AT9) is bigger, more wind load and more easily knocked out of whack by the wind.
the single and triple LNB dish mounted on the 1-5/8 OD J Bracket or Pipe, if you had it ground mounted.
The NEW 5 LNB Slimline mounts on a 2 inch OD J Bracket or in my case a 2 inch OD pipe that I sleeved with 2 inch ID PVC electrical conduit. I didn't want to see a rusty pipe.
Here's a pic.