You do know that HD2 audio streams are part of the same bit stream as HD1 channels don't you? You talk about HD2 channels like they are something separate. They aren't.
I'm not honest about DX'ers? No idea what that is supposed to mean. The DX hobby represents about .000001% of radio listening, and 000000% of anything that broadcasters care about.
I live in the Washington DC Metro area, where there are numerous HD stations between DC and Richmond, VA. Unless I'm way out on the fringe of either market, I have no long drop-outs for HD-anything. It may switch back to analog if in a rough area in the fringe, but as David already explained, except for NPR affiliated stations, HD2 channels are mainly for translator feeds or a beachhead for future use.
I want to thank you for elevated the discussion to a more civil level! Now we have a basis to talk.
Of course I know HD2+ are part of the same digital stream. I am talking about the radio ads promoted a few years back by the HD alliance - who encouraged people to discover the "stations between the stations" - I think that is the wording. It definitely implied to me that the broadcasters were intending for HD-2 to be a separate station, completely separate from the HD-1, except for the fact it is parasitic on it - a fact that consumers really didn't have to be concerned with or even know.
Washington DC may be a different case, but in Houston the HD-2's are broadcasting formats not available anywhere on HD-1 / analog. Christian rock, smooth jazz, indie rock, oldies, 80's, R&B oldies. Some really unique stuff, while the HD-1 / analog is of no interest to me for the most part. That is just to me - but I suspect there are others who like the HD-2 format of stations, without caring in the slightest about the HD-1. A good example is legacy KCOH - R&B / soul / minority centric programming on and HD-2 of a country station. Probably close to ZERO interest by one group of listeners in the programming on the other channel. KKBQ country music listeners probably don't care about KCOH programming, the KCOH people don't care about KKBQ programming. The KCOH crowd is probably aware that their format piggybacks on a country station, but if HD-2 goes out long enough that their radios revert to country music - they will not listen. KKBQ listeners who inadvertently hit the "up" button and get KCOH will soon re-tune. Zero overlap - KCOH is effectively a different station with its own audience.
Obviously I don't see David's assumption that HD-2 are translator feeds being true here in Houston. In fact, the one such case here closed down operations. It is certainly one use, but the experience in Houston is that HD-2's are developing their own identity, their own audience. In the case of NGEN radio - actually moving to an analog signal in a couple of months. Obviously, that, too is a use of HD-2.
I am glad you aren't experiencing dropouts, they are all over the place here. The latest dead spot I have identified is Greenhouse and I-10 for KRBE - a full class C about 15 miles from that location. There are numerous other momentary dead spots. But if you are stopped at a traffic light, KRBE HD-2 oldies - a separate radio station - is silent for the duration of the light. Dead air is never an inducement for listener loyalty. I hit the button to go to something else, knowing that the dead spot is as dependable and repeatable as things get in radio.
Oh - I meant honest about the prospects of HD-2 when dropouts abound. I am not talking about an HD-1 where there is a fall back to the analog channel. I am talking about HD-2's, programming as their own radio station, dropping to dead silence for ten seconds at a time, or more if you are in a dead zone. NOBODY - not even me - tolerates a minute of silence waiting for the light to change. HD-2 is a concept that failed, and HD-1 is not an improvement for 99% of listeners, so HD has no real advantage to the average consumer. THAT is what I am talking about. A DX'er only has more tolerance for dropouts, and therefore dis-proportionally more apt to use HD radio.