My answer is for the second part of the question. I can't conclusively judge whether this is the case with speed; however, I would say this: I have 5 of the pieces (4 TB) and they are by far the fastest and most useful mobile storage devices I own. Sustained 2GB/s is hard to get and certainly not over a long period of time and definitely not with macOS' own tools (Finder for example). My experience with M2 Pro (2022), M1 Air (2021) and Intel Pro out (2020) are extremely positive for me and I would buy this SSD again at any time. Unfortunately, they don't seem to be available in 8 or 16 TB yet, otherwise I would have bought a few right away. I use it mainly for accessing videos and photos when I switch from one device to the next, as a second backup of macOS installations and for Parallels machines, which I don't need that often. For me, the optimal tool for pushing the speed a little is Carbon Copy Cloner. Also, please never forget to switch off any virus scanners, memory optimisers, cloud storage scanners and other tools that could interfere. Otherwise the high transfer rate won't work. I would estimate the sustained rate at around 400 - 500 MB/s as realistic.