Inadequate for Android Marshmallow Adoptable Storage
The write speed of this card is not fast enough for use as a memory extension for an Android phone running the Marshmallow version of the OS, where you can use the SD card to replace the internal storage, which on some phones like my own is extremely woeful, where even when moving as much as you can to the external SD card, the OS directories simply fill up with data on a regular basis. Trying to use this card for the adoptable storage feature simply does not work as the write speed of the card is too slow - the attempt to perform the internal format actually times out, although if it completed I'm sure it wouldn't offer a great use experience. For other users in my situation - you need a U-3 class card at the very least - the UHS-I designation does not provide a useful guarantee of write speed as the class range is too broad, as in the case of this card where it is rated UHS-I, but also U-1, not U-3.
In addition, the product description is an outright lie as it specifies the card has 'Class 10, Grade 1 U3 Speed Class transfer speed with up to 80 MB/s', but this is not true as this is only true for the read speed - the card states U-1 for a reason and U-3 cannot be used as a description of read speed alone as it requires a minimum write speed of 30mb/s, which this card does not meet.
As the card itself otherwise functions correctly and has very good read speeds I'm not leaving a one-star review, but I cannot use the card for the purpose I bought it.
