Hi! I just gave up my iphone 5 for a Galaxy S5. It is an amazing work of art! I love the fact that I can add an expansion card but I'm a bit confused... I want to get the 128 GB version but I notice they come with different speeds... 400, 600, 800 and 1000. Does anyone know which is the best one to get and will all those speeds work with the Galaxy S5? Thank you!