In one day of use of the HP ENVY All-in-One, here is what has happened:
Carbonite was installed, and did the complete 34G backup in about 18 hours. It really did speed up when the system wasn't in use. The backup was complicated by the fact that the Geek Squad backup actually has a second copy of everything under :Desktop".
Windows 8 froze once, This happened in Google Chrome when browsing a complicated page on cnn.com. Chrome was trying to locate a particular ad file (I might have passed the cursor over). I had to turn off the machine and cold boot. It took a little longer than usual but then everything worked. Windows 8 does not warn you that it was not properly closed down.
Overnight, Windows applied a huge number of 8.1 updates to the new computer. The Restart process, with all the configuration steps, took about 20 minutes but worked OK.
A while ago, the HP gave a blue screen with a hard drive error. No f-keys worked. I simply turned the machine off and on, and the machine booted normally, although it took slightly longer than usual. Then I closed Windows normally, turned the machine off, and then rebooted and it was very fast. The error may have occurred as the computer was going to sleep when I was away from it to make lunch.
I went into the HP Support Assistant and signed up for all the crash reports and automatic notifications of firmware downloads
HP has a writeup on hard-drive errors, here. There is a firmware system called SMART which warns of hard drive failures. The writeup admits that "false positive" errors can occur. It recommends defragging the hard drive frequently, which Microsoft Action Center in Windows 8 is supposed to do. The Action Center did not show the failure in its Reliability Report.
Update: Aug 14
The Hard Drive Error occurred tonight, after I had let the machine go to sleep after a successful Windows update, which was massive. The machine started OK when turned off and on. I found some of the updates had failed. I redid them, and they worked. Then I closed the machine normally. I cold started it normally. It seems that I don't have a problem if I do a cold normal start shortly after finishing an update. HP has a firmware update scheduled Aug 17. This sounds more like firmware than hardware per se. Will take a picture if it happens again. May ask Geek Squad in a phone call tomorrow, Best link seems to be this.