I'm thinking about getting one installed (looking at upgrading Sat and TV's from SD right now) versus the Winegard or Motosat.
What I've heard is that initial setup/scan time once you're parked is significantly reduced (from 10 min down to 5 min or so, which still isn't exactly short) because of the GPS technology they have.
It also has the DirecTV SWM technology, which I'm very familiar with (I beta tested), which allows a SINGLE coax cable to penetrate the roof (thus allowing me to reuse the coax from my old SD round dish). SWM then uses just regular splitters (if they support the right frequency range) and then a single coax to each of your DirecTV receivers, even with multiple tuners. All the recent DirecTV recievers support SWM directly, and no more B-Band converters.
So for example with a single coax through roof, you can run coax to a main sat reciever, and with a splitter run also to a secondary receiver, and tune two channels in each, all at the same time. So can be recording 3 shows, watching a fourth, or watch two shows and record two, etc.
SWM also supports ethernet distribution, which then supports what directv used to call (in beta) MRV, Multi Room Viewing, now they call Whole Home. Basically each reciever can see the playlist on all of the receivers, and a non-DVR reciever (standard H24 say) can record to another DVR, so you can have a single DVR, and a separate non-DVR tuner, and both are able to record or watch shows.
I haven't verified that MRV is supported with the RF Mogul, you'll probably need an Ethernet router of some kind to act as DHCP server to give out IP addresses, not sure if they need a live internet connection (certainly there's functionality like On Demand that will work), I've never tried with a router to server DHCP but no live connection. It's possible that static IPs could be manually assigned between the two receivers to get whole-home to work without a router. Don't know, never tried, never needed to. I'll likely go with a single DirecTV tuner, and distribute the video to the two sets (which is what I have now) as we don't need to watch separate shows front/rear, and it simplifies things, plus saves a per-month charge for a second D* receiver.
SWM is definitely a more future-proof technology, all of the new DirecTV boxes use it, it's the standard technology for all their residential installs (single hole through roof, single cable to all reciever etc., makes installs cheaper, plus it has the internet distribution functionality).