Review on ProGrade Digital microSD UHS-II Dual-Slot Memory Card Reader 3.2 Gen 2 for Professional Filmmakers & Photographers by Blake Mannasseh

I bought the dual microSD card version to try and reduce the time I had to transfer from Need video from two GoPro cameras that I use to record the days I rode my motorcycle. When I do multi-day tours, I need a lot of time to transfer the video at the end of each day when I arrive at the hotel. Arrived (30 minutes ago) and this is what I found. When transferring video from a single MicroSD card (SanDisk Extreme 256GB A2), the average transfer speed on MBPro (Late 2016) to the built-in SSD was 54MB/s. This is three times faster than the inexpensive card reader I've used before. That's a good result. Not good. I expected it to be close to the advertised 100MB/s to 120MB/s which makes it great. 3X faster transmission is good, even very good, but not great. The second test is the simultaneous transfer of 2 MicroSD cards. I used identical MicroSD cards (again, SanDisk Extreme 256GB A2) each with 30GB of GoPro video. HERE THIS CARD READER SHOWED WHY IT IS SO EXPENSIVE. The average transfer rate was 61.9 MB/s for the first transfer and 62 MB/s. for the second course. Why the single double transfer speed is higher than the single transfer speed I can't say, but this score went from good to very good to excellent. I look forward to the 2021 touring season where I expect to be able to cut video copy time from 8 hours nightly to 1 hour 30 minutes (512GB transfer at 55MB/s vs 17MB/s).