SPOT really is kind of fun for recording where you were along the trail, though IMO this isn't important on marked trails where it's pretty easy to determine that anyway.

Some SPOT models now also offer the option of sending a short text message.
Nice to have some value from the device even if no emergency ever occurs.

FWIW, in using mine daily for some months I don't think it ever missed --- i.e., reliability seemed good to me, despite some things I had read earlier questioning the reliability of the underlying satellite network that SPOT uses.

The thing I like least about SPOT is that, insofar as I can tell, you can only buy a year's worth of service, for about $100 (and then there are optional additional services). The catch with that is that for my use at least, I'd rather be able to activate it for a month, or a couple of months at a time for a lower rate. I'm certainly not going to pay $100 for a year of service if I only anticipate using it on one trip for a couple of weeks. So now my SPOT sits on my shelf, lonely and unused.

I have no experience with or knowledge of true PLBs.

In terms of deciding whether to get a device like this, for me it would be very much about where and when I was hiking. If mostly on well-frequented trails in normal "hiking season", then even hiking solo I would be disinclined. Unless a family member was unhappy without you having one --- in which case, having a "not an emergency" checkin capability would be nice I think.