Actually I'm not sure if the app will allow connecting to a remote DVR if you have a local DVR. You may need to disable Bonjour on the local DVR web ui
I'm pretty sure that you're right. The app kind of freaks out when you try to connect to a remote DVR but a local DVR is visible. (I've never reported the issue before because it's such a weird use case, but I guess I'm not the only person who ran into it...)
@cemjack: For what it's worth, if your parents have 1gbit up, and you have a decent (50mbit+ down) internet connection where you are, you probably can get away with not transcoding at all . So a DS718 might be overkill...you can probably get by with a cheaper NAS without transcoding hardware. (That being said: if you want transcoding for mobile viewing over cellular, or if your home internet connection has a monthly data limit, or if you want faster commercial detection, then it's still worth spending extra money for a faster NAS.)