I went looking for this product because it was on sale. It wasn't on the shelves but I noticed a similar product that wasn't on sale but was comparable in price and went to the nearest desk and asked the difference... he laughed, reached into a stack of the sale items, put it in my hand and said THAT'S the one you want. I asked, but whats the difference? He said the reading and writing speed is way better on THIS one (The Samsung EVO) I thought in my head, 'It can't be THAT different.' I took his word for it and after some time decided to put into my tablet and downloaded some movies 14 GB of movies. It took less than half the time it would've taken with my older card. ( a few hours, granted on a slow connection that I've used before) So i guess the write speed DOES make a difference! I' haven't watched anything I've stored on it yet, so I cant comment on the Reading speed. but if it's anything like the writing speed, I'm sure I'll have no trouble! Samsung has yet to prove me wrong when I say they make top of the line products and is a very underrated company. Great for the money, Highly Recommend! Word of advice - this thing is SMALL so be careful not to lose it! I recommend saving the package it came in, cutting it in half - I prefer to keep it in it's adapter, in half of the case it came in so as not to lose them amongst the mess that is my desk! Enjoy!