Bests & Worsts Reviews from Amazon

In a nutshell: After multiple tests, this USB stick delivers close to its promised Write speed, but not its promised Read speed. However it's still quite fast, and a pretty good USB stick. IMPORTANT: Though the promised READ speeds are the same ("245MB/sec"), the promised WRITE Speeds on this stick VARY SIGNIFICANTLY depending if you get the 16GB (55MB/sec), 32GB (100MB/sec), or 64GB size (190MB/sec) size. I bought TWO 16GB size ones with the newer packaging (that promises Up to 245MB/Sec Read and 50MB/sec Write on the package -- though online for the 16GB size unit, it promises Up to 55MB/sec Write). When I originally tested it for speed, I was getting 27-29MB/sec Write MAX because I was using an old USB 2.0 extension cable (my fault), so I then inserted the USB stick directly into the 3.0 jack on my computer and tried again. I have now run multiple speed tests using multiple benchmarking programs, and the new (faster) results for these tests are very similar to each other. System: New Gateway Windows 7 Quad-Core desktop Machine (only a few weeks old), that is fast, lean and not bloated. USB stick had no files on it, computer resources were not being used, tests were run clean over two days using multiple different programs, with usb stick plugged directly into the 3.0 jack of my new computer. The speed will change with the type/size of file being written/read to the USB stick, but I put up the best numbers for each of these tests (and they were surprisingly consistent): Crystal Disk Mark Test (Best numbers): Read: 180.5MB/sec Write: 48.73MB/sec RoadKil's Disk Speed Test (Best numbers): Read: 174.26MB/sec USB Flash Benchmark Test (Best numbers): Read: 173.08MB/sec Write: 44.27MB/sec AS SSD Test (Best Numbers): Read: 169.16MB/sec Write: 49.69MB/sec So these numbers are pretty good... but they don't reach the promised "Up To" speed, especially the Read numbers. The write numbers actually aren't bad: the promised speeds were "50MB" (on package) or "55MB" (online for this 16GB model), and the delivered write speeds of 49.69, 44.27, and 48.73 were close enough to the promised speed for me. Where it lagged though, was in the Read numbers. The best numbers for each test were surprisingly similar: 180, 174, 173, and 169 -- fast, but still pretty far away from the promised "Up to" speed of 245. If the Read speed was as close to the promised speed as the Write speed, I'd give 5-stars... but with the larger shortcomings in the Read speed, I'm giving it a still-respectable 4-stars. There are two reason I can think of for this difference in the Read speed numbers from the promised speed: (1) It could be my system, of course... but it's a brand new, fast Gateway Quad Core desktop with USB 3.0 jacks, so I tend to think not (especially as the Write speed numbers are close to the advertised write speed). The machine is lean, not bloated, and system resources were not being used. The tests were also done over 2 days with multiple benchmarking programs. (2) It could also be that, even though the units I ordered and received had the "Up to 245MB/sec Read" printed on the packaging, maybe the units put inside the packaging and sent to me were actually the OLDER ones instead (which I believe promised "Up to 190MB/sec" Read speed). This would make the Read numbers I keep getting pretty close (to 190), and right in line with how close the Write numbers were. If this is the case though, then SanDisk put some older (slower) units in the newer packaging. If SanDisk support is reading this (from India I assume, seeing the British spelling and word usage used in their other replies), is there a way to tell from the serial numbers on the units if a unit is indeed of the newer batches that are supposed to deliver "Up to 245MB/sec" or the slightly older ones that only went up to 190MB/sec? Other than the speed, these USB sticks are very lightweight, made of hard plastic, are retractable (locking retractable -- which is great if it doesn't break in time), and have a tiny, subdued blue light that flashes as data is being read/written to the stick. In conclusion, this is a pretty fast stick, but while I indeed get very close to the advertised maximum Write speed, the Read speed don't come as close. Still though, a decent stick. Personally, I'm more concerned about Write speed than Read speed, so I'm happy with these (and who knows, maybe you'll be able to get closer to the Read numbers than I was). Hope you found this review useful!