I'm very sorry if this has already been answered but I couldn't find it. My HR20-100 seems to be going out and I would like to get it replaced. D* said that they could send me a HR21 but they couldn't give me a HR22. I'm pretty sure I can get an HR22 if I push the issue (I've been a customer for over 5 years). I haven't been able to find a whole lot of info about the HR22 except that it has a larger hard drive. Should I get the HR21 or the HR22? Can you use a external hard drive with the HR22? Are there any major differences between the HR21 and HR22? Any info would really be appreciated.