After spending most of the afternoon attempting to download the installer, it finally completed without error.
I set up a separate partition on my hard drive and installed it.
Very pretty. "I love what you've done with the place."
After about an hour, I got bored. There isn't much I could do with it, because I only allotted a 60GB partition, and while I might've been able to reinstall all my applications, it definitely wouldn't hold all my data, and frankly I just couldn't deal with all that bother anyway.
I have too much on my internal drive to just split it down the middle and restore everything from Time Machine, so I decided to load it on an external drive.
That worked fine. It was impossibly slow, but I verified that everything worked.
After creating a complete backup of the existing internal Mavericks drive, I threw all caution to the wind and ignoring all published warnings, I then loaded Yosemite on the main drive.
So far, so good. The only issue I've run into is that the GUI interface of my VPN service didn't work. That's not a big deal, as I was able to set up a direct VPN connection in the OS.