Its ordinary now to have several HDs employed, and once one of these starts showing failing signs, immediate intent is not to buy a replacement drive (it takes time and does require extra research given bad experience and a possible chance to repair), but to migrate existing setup on one of currently used drives temporarily, thus making the PC available for work.
Yep, but if the device is time or mission critical, it should have an adequate (and easily swappable) setup and backup.
This is more likely to pertain to "business" use than "average Joe" one, but having NOT a very current image of ALL your hard disks is a good way to risk losing data.
I mean, I do have a particularly critical PC that is used/accessed 24/7, with a hard disk dedicated to "system" and one to "data", but I do have also an identical PC ready with two hard disk - as well identical to the ones in the "working" machine, kept synchronized via Network.
If anything fails, even the smallest thing, I simply swap one or the other hard disk (or actually put into service the "spare" PC) and in no more than 15 minutes everything is up and working again, with - in the very worst cases - a few minutes of work NOT replicated.
The "old" trick that anyone can use is to have ALL your hard disks have a smallish "system" partition as first one, hosting a "base" OS, that is booted to image/backup/restore the "main" System partition (that I usually have on a second partition.
More generally DATA is priceless, OS installs are NOT, a "normal" user can well spend some time into backing up data regularly and re-install (or repair install) the OS.
But nowadays buying drives in couples, have one in an external enclosure and dd the main one on it is something even the metioned "average Joe" can afford.
I am pretty convinced that a repair install from the SETUP media can recover a situation like described, but cannot swear by it.
My rule of thumb is always get TWO smaller drives that a BIG one, the cost is usually very similar, and - from experience "top performance" and "high capacity" of newest model has often the drawback of a lesser - to say the least - reliability when compared to lower capcity, already widely in use, models.
About advanced tools I tend to try avoiding them as much as possible, they often give you the (WRONG) feeling you can do everything you want with partitions and filesystems (like moving, resizing, cloning, extend, etc.) which is normally not *needed* and that very often fails when you actually need to use some of their "advanced" features (but this is because you rarely test apporopriately the app in the actual scenario where at a certain point it's use it's needed).
I prefer to use "old", documented, tested and "simple" ways rather than rely on "automagical" software that claims to do everything (yes I did have my problems with Partition Magic and with Acronis apps at the time and I learned to never trust them without actually simulating their use BEFORE actually *needing* them in a "real" emergency).