OK...what I've got right now is, 3 HR20-700s. Yeah, they're old, but up till now, they've been working, with only a few problems. I've got 2TB hard drives connected to 2 of them, as we do a lot of recording. Well, recently, our main machine has been going unresponsive or extremely slowly responding...I mean 5 or 10 minutes per command. When I unplug, it seems to resolve for an unpredictable number of hours. Anyhow, I've been paying the "insurance" on these for years, so I thought I should take advantage of that, however it's been so long, I have no idea what units are good or bad. Also, I want to be able to add on my hard drives for more space, if possible. What is your recommendation. I do have 3 HD sets on those DVRs and my system is running off of SWMs, to work with our prewired-for-cable house. Thanks for the help!