HD Radio vs. Satellite Radio & Alpine HU's
 

Just checking out a headunit to replace the stock deck so I can finally get some real sound out of my speakers and I've have run into a few questions. Primarily I am looking at two HU's to install, the Alpine CDA-9853 and the Alpine CDA-9857. I originally was thinking the 9853 because it's a relatively decent price and has enough bells & whistles to keep me happy. Mostly the iPod & Sat Radio ready functions and removable faceplate. However the 9857 has all that plus the HD radio capability. My problem is that I dont know much about HD Radio and whether or not it is worth it or going to be worth it. That being said I'm worried about settling for Satellite radio since they are starting to air commercials now which is annoying and was one of my main reasons for being interested. I know this is the case with XM Radio, maybe Sirius is different.

Can anyone give me an opinion on the two decks and some input on the HD Radio vs. Sat. Radio issue?