It's interesting this thread popped up. I just was able to switch from 110/119/129 satellites to the eastern arc because of no LOS for 129 due to tree leaves sprouting that happens this time of year. (Imagine that!!!!????)
The signal from the eastern arc is "less" strength wise than 110/119, but I've had no dropouts during heavy rain or thick clouds. I have two receivers, a 622 and a 612. The dish is 15 feet up, mounted on a C-Band satellite dish pole with about 100 fet of RG-6 cable run to my receivers.
The technician told me the signal strength would be better if we relocated the dish closer to the house and have a shorter coax run from the dish. I have had no issues, SO FAR. And as long as it continues, I see no reason to change the location.