The Kingston V300 is an entry level model that has developed a problem. Initially the Kingston ssd used 19nm MLC Toggle Mode NAND flash memory manufactured by Toshiba. About 6 months ago Kingston switched to 20nm Asynchronous Nand flash memory manufactured by Micron. That's when the problems developed. Some ssd's worked according to specifications and some did not. Some consumers who purchased the ssd's with problems accused Kingston of using a "bait and switch" tactic to generate higher revenue. I was never able to find into a published news article indicating that Micron had a problem with flash memory. Normally when a problem develops an ssd company tries to find a solution and then issues a firmware update. Kingston issued several firmware updates. Sometimes the updates solved the problem and sometimes the firmware updates did not solve the problem. Last month AnandTech published an update indicating the Micron memory was slower than the Toshiba memory. AnandTech also mentioned two review sites tested the ssd's and confirmed they were slower than the original version of the V300.
The Samsung EVO is a much better ssd with a proven track record.