I started out with an Intel X25-M 120gb for my first SSD. Flawless performance and reliability. Fast Forward: New build, and in need of a SATA III SSD. Read hardware reviews saying Intel has worked on new Sandforce controller for their 520 series of drives and has ironed out the bugs...in other words, they've "Intel'd" it. Ordered computer components from Newegg which included the Intel 520 120gb SSD. Installed components, and SSD worked great for a day. Next day, blue screens all day long. Did research and some of the blue screens are the same as the "Sandforce" blue screen. RMA'd drive and got another Intel. Installed and ran for about a day then more of the same.....blue screens. Called Newegg up, told them what was going on, got my money back on the Intel and purchased the Samsung 830. Installed the new SSD.........no problems since. Now I'm not saying all of the issues was with the Sandforce controller on the new Intel 520 drives, but my old X25-M is still working and the biggest difference in the two are the controllers.
On a side note, benchmarks of the Intel 520 on incompressible data was just downright crap. ATTO benchmarks were some of the highest I had ever seen, but throw AS SSD on it and the Seq. WRITE numbers were only about 20MB/s faster than my Intel X25-M SATA II drive. I know Sandforce delivers great numbers with compressible data, but I thought the numbers I were getting were extremely low. The Samsung drive produces the same numbers no matter what kind of data it is testing.....and more importantly, has not thrown any blue screens up. I really wish the Intel 520 would have used an updated Intel controller like the X25-M, that would have been nice.