Question U.2 Drive and PCIe adapter

Why would you want to bother with U.2 drives which are not particularly common and offer no real benefits over M.2 drives, when M.2 NVME drives are far more widely supported in terms of form factor on both motherboards and adapters?

What are the specs of the system you are intending to use this in?
 
But there is nothing wrong with SK Hynix if the performance numbers for a given drive are similar and the price is better. Between the two I'd usually opt for Samsung because it is usually more readily available, but SK Hynix is a DRAM and NAND manufacturer like Samsung and they have good quality products with good performance characteristics for most of their NVME drives.