I'm currently buying a little USB 3.0 Flash Drive to run another operating system from on my lappy, and for this the read/write speeds matter a whole lot more than gigabytes per buck. Suppliers are VERY poor at supplying this essential information, and you can waste a fortune buying them to test them yourself. But, here's a site that supplies objective comparisons so's you can make the best decision. Certainly one to bookmark on your smartphone or tab to spot bargains while you are out shopping. http://usb.userbenchmark.com/ What's particularly useful is the effective speed assessment - raw read and write speeds are not the full story! (S)He has also computed a value for money figure, and you can sort your list on any of the criteria by clicking on the column title. Remember that unless your computer has USB 3.0 sockets you aren't likely to see anything like the quoted performance on the faster products. USB 3.0 sockets generally have a tab in them that's colour-coded purple against the usually black USB 2 type.