For those of you considering the new X10 transmitter/receiver wireless products, here is my latest experience:
I recently bought an X10 A/V 5.8GHz Plus system with remote and second receiver and after some trial and error got it to work fine with my Direct TV feed from my second DTV receiver. In addition to my big family room TV (the one with DTV's DVR), I have three additional TVs scattered throughout the house: in the downstairs bedroom, dining room, and upstairs kitchen.
I installed the X10 sender to my DTV second receiver in the downstairs bedroom and fed the DTV signal from this module to the downstairs dining room and upstairs kitchen. I now enjoy the convenience of viewing my three additional TVs for both DTV live programming and recordings in my play list I then plugged the X10 remote extender cord into the sender unit as shown in the manual. The picture and sound are excellent, with minor noise and interference, and the remote works perfectly from all locations. (BTW, I have an AT&T U-Verse wireless network and a set of four 6.0 GHz digital phones installed and working in the background—not to mention a couple of microwaves. Still, virtually no interference).
My new X10 system is definitely better than the earlier 2.4GHz X10 modules I used earlier. I did find some SNAFUs, though: (1) I had no problems installing the downstairs bedroom or upstairs kitchen X10 receivers, since their TVs have RCA inputs. My TV in the dowstairs dining room, however, had only a coaxial input. I tried an RF converter (modulator), a GE 23298, and had a lot of interference and instability. If the TV you're playing with has no RCA cable inputs, I DO NOT RECOMMEND USING AN RF CONVERTER WITH THIS X10 SETUP!!!!! Rather, dig an old VCR from your closet, one with two I/O coaxials and three RCA A/V inputs. Using this setup, I have excellent results, with the advantage of saving to tape (ugh!) any program sent to this TV-VCR combo! (2) Read the X10 manual and follow directions TO THE LETTER. When the manual says that there is ONLY one reliable way to connect the X10 receiver to an older TV with coaxial input, they mean it. A VCR (NOT an RF converter) is their recommendation. (3) Tiny adjustments to the X10 sender/receiver antennas make HUGE differences in the transmission and reception. Experiment to find the optimum positions.
All in all, the $100 paid for my new X10 5.8GHz wireless transmitter/receiver system will save me pots of money with my DTV service, since I will avoid rental costs for my extra TV feeds. Remember: Read the manual, follow directions explicitly, be patient, and experiment.