R/W speeds as advertised, good and fast.

Extremely poor physical durability, see below.

I bought two of 32gb versions of this card to use for a project on my Raspberry Pi. Within about a month, the coating that protects some of the contacts on the back of the cards was flaking off, and it caused the data on one of the cards to corrupt. This is extremely disappointing as I bought Sandisk specifically because their other cards I'd used in the past (either Sandisk Ultra or Sandisk Extreme) have held up so well when other cheaper ones failed eventually. Sadly these appear to be the "bargain bin" of Sandisk U3 speed cards, and don't hold up physically. Would probably be ok installed in something where they won't be removed often, but if you need U3 rated cards to survive frequent unplugging/re-plugging, go with the more expensive "Extreme" series instead! Those cards haven't failed me yet.