I will need to watch this video a couple of times before I totally understand it.
https://www.youtube.com/watch?v=ZlWhvc-UCOA
He matches a cheap ($17 USD) Trenscend Card Reader performance with that of a more expensive ($79 SD) Prograde Card Reader using two speeds of SD Cards.
The Prograde Card Reader seemed to do a lot better than the Transcend. I wonder how my Lexar Caed Reader (which I think that Manfred also uses) would stack up against te Prograde Reader...
Of course speed is really only important if you are working with large numbers of files or with video (especially 4K video). And, of course, all cameras cannot take advantage of the fastest SD Cards available.
What do you think folks???