What is Optane? What is Optane good for?
Oh, right, not doing link only answers.
Optane is one of Intel's brandings for a new-ish type of non-voltaile storage, known as 3D XPoint—as well some associated "technologies", because confusion is good (more on that in a bit.) Optane sits in between RAM and NAND flash, being cheaper but worse performing than RAM, and faster but better performing than NAND. However, it sits closer to the NAND side than the RAM side. Compared to traditional NAND used in "normal" SSDs, it has two main advantages (endurance and latency) and once disadvantage (price.) So, unless you have massive amounts of money to spend and simply want the best of the best, Optane is best used as a sort of scratch disk, where frequent read/writes won't impact longevity and the strong random access times shine. This is particularly useful in a number of professional applications.
On the consumer side, Intel is marketing Optane as a sort of cache for frequently used files/programs/other data. The idea is that frequently used data gets migrated off your SSD or HDD, onto a (relatively small, 16GB or 32GB typically) Optane module, speeding up performance for that set frequently accessed items. This is the same concept as with an SSHD; however, instead of the cache being NAND, it's a larger 3D XPoint cache.
However, this is where things get... annoying. As with an SSHD, this process is supposed to happen silently, in the background, without user input. Unlike an SSHD though, because the modules are separate, it can't be handled by the drive controller. Intel therefore handed the job to the CPU and chipset (and required associated software.) However, Intel restricted their support for this to 7th Gen CPUs/200 series chipsets and newer. To denote this, Intel (and associated partners) started marking certain other hardware, including prebuilt computers, as Optane ready. However, the drives themselves will work fine in other systems; it's just the automated caching. This can easily be replaced with other sofware, such as PrimoCache on Windows—while adding additional features and flexibility, such as the ability to use regular NAND flash.
Should I get it?
No. Probably. For the Optane modules themselves, the performance difference in "normal" use, compared to even a mid-tier SSD, simply isn't noticeable or important in everyday use. While it might be useful within a very narrow use case (e.g. creating many different VMs while utilizing a few shared resources), it's probably not worth it.
As for anything marketed using the Optane name, there's no reason to pay extra. Intel's software isn't any better than other solutions, and all it really means is that there's a bog-standard NVMe-compatible M.2 slot that you could install an Optane module in. It's certainly not a reason to compromise on anything else. Get whatever fits your requirements in other areas (we can help!), if you want to install Optane (for some reason) make sure there's a free NVMe-compatible M.2 port, don't bother looking for Optane branding.