So we've had a few days now with the HR21, and I have to say, it's nice. As I said in my last post, I don't particularly miss the TiVo menu system. The HR21 shows a picture-in-picture view of the current program while you're in the menus or in the guide, unlike the TiVos. I also hooked our receivers to the network, which enabled home media viewing and DirecTV on demand. It took a day or two for the on demand feature to work, but now that it does, it's quite compelling. I've already downloaded an episode of Californication that Scarlet had missed from last season (of course, you can't get shows on-demand for channels to which you do not subscribe). They also have some extra channels that have concerts, Olympic stuff, and even an Adult Swim VOD channel.
Among the new niceties with the HR21 is that PPV events now are not charged until you actually watch them. It is free to record a PPV event - or even download one with on-demand. You only get charged when you start watching it. The downside is that, like iTunes rentals, you have a 24 hour window in which to finish watching.
The AM21 seems to work pretty well. The only quirk is that although we've selected "channels I receive" as the default guide, the over-the-satellite local channels still show up, even though we don't actually get them. This means that when you're picking a show to record, you have to make sure to pick the one that is over-the-air. Fortunately, they're easy to spot - they have a sub-channel number (like 9-1 instead of just 9).
The HR21s have an eSATA port on the back, which allows you to replace the internal hard drive without any tools. I don't know if we'll take advantage of this or not. Unfortunately, it doesn't cascade the two drives, so when you plug in an external drive, you lose access to the recordings on the internal drive. But adding a 1TB drive (and they're not that expensive anymore) would triple the capacity. Time will tell if that is necessary or not.
Wiring the system up with the SWM module was just as easy as wiring up any older multi-switch. I decided to keep the terrestrial wiring separate, but the SWM-8 does have a terrestrial input so that you can diplex everything together. DirecTV apparently has a new LNB in the works that integrates an SWM-8. That will make DirecTV much more like cable TV than it is now - just one wire leaving the dish that can be split with ordinary splitters as many ways as desired (feeding up to 8 tuners). But with the SWM-8, you can achieve the same thing right now if you want (though the SWM modules are not cheap, unfortunately).
There's only one feature missing from our setup that I'd like to see added - the ability for two DVRs in the same household to share content over the network. Right now, I have to set up a series link (aka season pass) for The Soup on both DVRs to be able to watch it in either room. If DirecTV would allow sharing content over the network - even if they don't allow downloading directly to a PC - that would be just about perfect in my book.