I really like HD radio, when it works. I have an $80 Dual brand head unit in my old van and as long as it keeps the signal it is clear as a bell and gives plenty of content options otherwise unavailable (with noticeably fewer commercials!). But the cost to buy and install an OEM integrated tuner add-on (no way I'm pulling the original radio or having some extra box thing on my dash!) is about $279 - $325. One year of satellite is about $160 from what I've read here. So my question is, does the satellite signal cut-out a lot less than the Hybrid Digital one does, if at all? If it does keep the signal better, I'd go for the subscription and not have to worry about anyone messing up the installation. I'm sure satellite also has more content options but I've never had a satellite radio so I wanted to hear it from someone who uses it. I know I could just wait to get the car next week and test it for 3 months, but hey, what is this forum for if not to field these kind of questions? Besides someone else without the SAT option may be wondering the same thing.
There's plenty of XM content available - I like it a lot. There are unregulated channels, but there is also radio Disney and other content that is specifically 'family safe'. Lots to choose from... hundreds of channels. I cannot compare to HD, since I've never had that, but I can't see how you could want richer content. As for the reception quality, that's another matter. That seems to depend a lot on the area in which you're driving. I have my share of annoying dropouts, more than with my previous standalone XM unit, so I can only give it about a 6 out of 10 on the reception question.
I went to hdradio.com and found this: HD Digital Radio • IT’S TIME TO UPGRADE! It integrates with the existing radio, which is important to me. I really wanted to get the HD for more news channels, and the SAT subscriptions for news channels are more reasonably priced than for the full SAT packages. So I don't think I'll go for HD right now. If HD were under $100 I'd go for it.
Really, I didn't see that option on the website. Are you sure it is still being offered? Can it be transferred to another car if/when you sell your current one and buy another SAT-equipped car? What if satellite radio goes away in favor of internet radio?
The Peripheral Electronics units listed on the link above may not be compatible with XM equipped 2010 Prius radios? The application notes for Toyota mentions an "AM-SAT" button on the OEM radio. They don't address the 2010 models on their web page. Are you sure the units will work with your Prius III?
Well, I never tried it, but my radio does have the AM-SAT button. I mostly listed that because I found it quickly, but I remember the other options were all the same cost +/- $20 or so. This one looked like the most complete.