I'm looking forward to buy myself a new MicroSD card for my Raspberry Pi 3. It is Kingston 64gb Class 10 Uhs-1 And here is Question: Will this work with Pi 3? I heard many stories about cards not working, and I want to be sure. Seller claims that it MicroSDHC, SDHC and SDXC support. Does anybody know if it will work?
Yes it will work. The Pi does not support the protocols (or have the hardware) required to implement the higher speeds such as UHS, but will operate.
Any Class 4, 6 or 10 card will work - the only difference between these is write speed (and this in burst mode). The read speed, which is arguably more significant for the Pi, depends on the manufacturer.
You can check if your SDCard has been tested here http://elinux.org/RPi_SD_cards and see the results. Probably it will work without problems. Also you can add your test if there isn't available. You can help other people.