I had nothing but problems with 129 and the 1000.2 dish. They just switched me back to the "two dish" (Dual 500's) set up, that I had before, and 129 is great. The 1000.2 dish was under "designed/manufactured". It does a great job of grabbing two birds but the third is so so. As per several Senior Techs/Field Supers and from my experience at Hughes Aerospace. I had two dishes then told I had to have the 1000.2 when I got a 722. Nothing but problems since. Then I was told that not everybody was having success with this model of dish and were/are being moved back or to the two dish set up. They say there was not reason to have changed it. I had no issues with 129 prior to the 1000.2.
So a two dish set up is logically the best. Each bird will get it own LNB and more precision individual alignment.