I'm in north Florida and have had the two dish set-up for quite a while, but when I moved Dish set up the new single dish that does the same as what the previous two dish system did, and with this changed the local channels to HD instead of the SD. They used the exact same DVR as before (vip612). Of course you can use an antenna for the local channels, but I just keep it simple and subscribe to them through Dish. It does look better than the multi-dish system.
According to the tech that moved my wing dish last week, West Palm gets Eastern Arc, but the Miami DMA gets 110/119 and 129. Our locals are on 110/119. Most of the other HD is on 129. Seemed weird to me.