I hate to repeat this again and again and again.
Sequential speeds are worthless. Your usb bus will most likely limit you to about ~25MB/s, that's the kind of read speed you will get if you read files from the phone. Writing to the phone from the PC is very unlikely to exceed ~15MB/s, provided you do a sequential write.
Within the phone, the files are scattered everywhere. Unless you are reading/writing a chunk of a single file, e.g. reading a HD video, or recording a 4K video, having high sequential read/write speeds are worthless. Even so, a Class 4 card can playback a HD video without lag. The camera doesn't take photos in raw format thus the file size is still relatively small (except in burst mode).
Showing people how fast these cards perform sequentially is very much useless since they are all usually very much slower when accessing random locations, which are more akin to real-world usage. You are better off getting spending your money on the cheapest 64gb card from a distro with a good rma process.