Instead, what I'm offered is a series of backup systems that back up everything, and if I want to restore, it'll put me right back to the point that caused the need for the restore in the first place, with no intelligence in file or data selection.
I know as a user that the answer's pretty simple, make sure that I do this myself, putting photos, videos and documents in a specific folder chain, backing that up regularly, and create a drive image after installing all needed software on a vanilla system. The problem is that the time I'm least willing and most time impacted is after spending hours and hours installing the operating system and applications.
 I can have a vague hope that Seagate has finally addressed this pressing need in the market, but I suspect, from the press release, that once again, they've simply made a new variation of whole system mirroring, resulting in hours long restore processes that simply put the system back to the point it was unstable.
Where you run into problems, is the registry on windows boxes, where system and user data is commingled such that restoring one or the other separately is difficult, if not impossible. 
I’m sure you know Ghost will do most of what you want. Install your O/S and all your base applications on partition C of 500gb hard drive Then make a Ghost image which will reinstall all this in ten minutes. Lets say partition C is 25-50 gigabytes
Partition D is what remains on your 50gb hard drive and is where you keep photos and documents. As far as backing up your images, photos and documents why won’t an external hard drive do it to your satisfaction?