My experience is that normal SanDisc SD cards are the best. Other brands are unusable because of latency of write/read time! You need to power them when you buy them though, otherwise they actually break sometimes, and I don't mean data loss; I mean break!

This means you should try to buy them as fresh as possible and since sellers don't show production dates that means you have to wait for new models to come out and buy them then.

To me the most important metric is not speed of bandwidth but speed of time and stability! Does anyone have measures of how the SSD compares to SD card in terms of write/read latency?

I have only had problems with USB <-> SATA, the stability of USB3 drivers is a joke!