SM2267XT here (TLC). So, the slower one. But still works fine after nearly two years of use for OS, drivers, and browser. CrystalDisk says the NV2 is at 98%, 16TB written. And that's after I moved the drive with 100% to the spot next to the GPU without a heatsink. And there it says 58°C, idle. That's noticeably higher than it was at the spot next to the CPU with a heatsink. But still fine. Not that the drive would get pushed much i.e. by the OS, which was designed to run on HDDs as well. And I did split stuff up on several drives, so basically I have like a stack of storage read/write capacity, run through 12 PCIe lanes, and likely adding a Gen5 at some point.
Even Gen3 is still a huge step-up from a Sata SSD though - not only because of the "max speed", but also due to having way more queues, which helps to remove a sort of "desktop lag" that can be easily seen on older rigs (incl. CPU) when there is stuff going on, like downloading and installing something (which takes up HW capacity), running the browser, which also wants to access something, such as RAM and that HDD/SSD, all on an internet connection which may in some cases exceed the speed of HDDs (like, what gets downloaded to the HDD, waits around the modem to be able to actually get processed onto the HDD).
So, what I am tryingto say is that a "budget M.2 SSD" is plenty for casual use of a PC. Even when one pushes for like 4K/8K gaming capability of a rig, or something, (such as being able to fill the entire VRAM within seconds, and a 12GB VRAM within a second with a Gen5 SSD), there is still some use for a simple drive, to chill alongside.