But it sounds like you're getting very good performance especially considering the age of the computer. You could try copying a larger set of images to see a more robust estimate of the transfer speed. But for now I have way more cards than I need, so. If someone has a lot of complementary XQD readers (like me) then these new XQD cards could be an economical option as well (the Sony CFexpress/XQD reader is pretty expensive). I noticed that Sony's latest XQD 64/120/240 GB cards support PCI express 3.0 and are a bit faster than the ones from 2016-7 that I have. Most computers aren't optimized to give the highest speeds with these cards, but perhaps newer computers in a few years make better use of them. To my recollection the Sony reader supports faster speeds with USB-C and Thunderbolt. (I suppose I could contact Sony or Dell customer support to ask about the port / reader incompatibility.) The desktop does have Thunderbolt support (do not know which gen) so I could test it with another Thunderbolt device to see if the port is faulty. On computers with Thunderbolt 3, I recall a web site reporting transfer speeds up to 420 MB/s with CFexpress so my setup is a bit behind but the desktop is not too far behind for me to be bothered about it in real-world use. On my laptop I get about 280 MB/s with CFexpress. On my desktop, the copying speed to internal drive from Sony 128 GB CFexpress (Sony 128GB) is 370 MB/s and about 270-320 MB/s with Sony 32 GB and 64 GB XQD G-series cards (from 20). The USB C to C cable works on my laptop but for some reason it doesn't work with my desktop's USB-C port.

I have the same reader and use it with the USB C to A cable that came with it on my desktop.

Sony xqd card reader review