johnvonmacz - I see we have another misunderstanding about the Samsung 840 Series SATA 3 6Gb/s solid state drives and the use of Triple Level Cell (TLC) flash memory. I've got another thread going about the Samsung 840 torture tests conducted by Hardware Info. The final update was posted this morning.
Here is the link to the other Tom's Hardware thread:
http://www.tomshardware.com/answers/id-1655789/samsung-840-ssd-tlc-nand-torture-test-update.html
Here is the link to the Hardware Info torture tests and updates:
http://uk.hardware.info/reviews/4178/hardwareinfo-tests-lifespan-of-samsung-ssd-840-250gb-tlc-ssd-updated-with-final-conclusion.
Hardware Info concluded that with an average lifespan of 75 years for the TLC memory chips, consumers have absolutely nothing to worry about. A Samsung 840 SSD with TLC memory is just as reliable as SSD's with MLC memory, and the type of memory should not be a reason to choose one SSD over another.
Finally the SanDisk Extreme and the Plextor M5S you mentioned are older models that have been replaced by the SanDisk Extreme II and the Plextor PX-M5 Pro Extreme
Inr3t1a - If you are in the USA, then you can purchase a modern 3rd generation, SATA 3, 6Gb/s ssd for less than $200.00 and still have some money left over. If you are in another country, then you may find that prices are higher. Availability may also be a problem.