I am a huge fan of my OTA HDHR. I have never messed with cablecard tuning (the flag stuff offends me so greatly I would honestly not play by the rules), but for OTA channel tuning nothing beats the flexibility and usefulness of a HDHR. Just be sure to treat it nice, I kept my first one in a bad spot (on the floor under an entertainment center) and it crappy out on me.
It is too bad that only WMC really plays with cablecard properly, or that more stuff isn't OTA.
No problem at all with that, and thank the Lord -- OTA isn't dead, but alive. OTA is the easiest way to get started. If your budget admits for it even with a plan to include cable in the mix, it should all "integrate" properly in a single PC (for starters).
After getting my HVR-2250 with OTA antenna and my HDHR' with subscription cable set up for my main PC, I never investigated further these other HDHR devices. Am I guessing correctly that at least one is a networked device . . . . lemme see . . . yeah -- the HDHR4-2US.
Like many, my family is indifferent to "televised-computing" or "computerized television." But I like the idea of sitting at my machine with a TV-screen in a small window at the corner of the display. Otherwise, I probably would've acquired one of those HDHR4 units, or played with one of the Silly-Dust extenders. Certainly, if they want it, the fam-damn-ily can get the subscription cable now with the six tuners in my two HDHR'-'s. But they all have individual STB's, so the interest-level is lower. . .
I can see how HDHR' and something like the HDHR4 could save us money. We're paying ~$7 or $8 each for the four STBs in the house. Of course, we'd abjure the On Demand feature, but frankly, I don't think anyone else in the house uses it. The stumbling block is the HDMI cabling between the additional PCs and the HDTVs -- some in other rooms. There are only so many Ethernet cable-drops in certain rooms.
Maybe someone here knows something about solutions to such things that I don't know.
Seems to me . . . if you have enough of these gadgets, you might replace your standard 4 or 5-port G-bit switch with an 8-port -- they're pretty cheap -- and pile all the devices up in some well-ventilated corner of a room somewhere.
When I added my second HDHR' I fretted over the clutter in my stereo cabinet because I'm always trying to manage the heat dissipation. I have a plan to add a fan to the cabinet with a small AC/DC power brick I bought for the purpose. With that, you could then stack the HDHR'-'s and the tuning adapters in a single shelf with space between the units to avoid any "cooking effect."