Although I have not done a benchmark, I see reduced boot times compared to a micro SD card, which seems to agree with the manufacturer's claims about the performance announced in 4k read.
The raspikey is recognized as a classic memory card so no software or special procedure to flash ISO / IMG images.
The shape of the raspikey makes it compatible with the various enclosures that I have.
I have just received it so I cannot have hindsight on the lifespan which would be superior to a micro SD card but the product is well designed and I do not worry about this point.
TL; DR: this is a product with which I am very satisfied