The SWM will allow you to run a total of 8 tuners. One line comes out of the SWM, which can be split with high-frequency cable splitters to get cable to the rooms you need it in. Only one cable needs to be connected to a dual-tuner receiver; it will get the signal for both tuners over the one cable.
The only issue is that, yes, it will NOT work with your HR10-250 (which you should really consider taking DirecTV's offer of a free upgrade for, since it will lose all satellite HD very soon). It only works with HR2x, H2x, R16, R22, and D12 receivers, and anything newer.
With the SWM, you could use the second coax for OTA, and get better signal than using diplexers.
The only issue is that, yes, it will NOT work with your HR10-250 (which you should really consider taking DirecTV's offer of a free upgrade for, since it will lose all satellite HD very soon). It only works with HR2x, H2x, R16, R22, and D12 receivers, and anything newer.
With the SWM, you could use the second coax for OTA, and get better signal than using diplexers.
