If you always camp where there are very few trees, the roof-mounted dish will be very convenient. I know that the portables are more work, but you can get one that automatically finds the satellite so all you'd have to do is connect it to the SAT IN on your Rockwood and you can keep it if you ever sell your trailer. If you camp in campgrounds with a lot of trees, you'd be better off with a portable dish that you can move to a spot with a better line of sight to the satellite.
2011 Rockwood Signature Ultra Lite 8293SS, 12K Equal-i-zer
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73
2010 Rockwood Roo 23SS (2012 - 2014)
2009 Ford F-150 XLT SuperCrew, 5.4L, 4x4, 5'6" bed (2012 - 2016)