The reason why Kingston has benchmark results similar to the EVO is the fact that the Sandforce controller compresses the data. If you are dealing with incompressible data (like music files, or anything encrypted), the performance difference is very noticeable.
Here, benchmarks done by anandtech with both compressible and uncompressible data http://www.anandtech.com/show/6733/kingston-ssdnow-v300-review/2
Performance-wise the EVO is superior, no matter how you look at it.
As for the reliability of the EVO, anandtech was also doing a test to see how many GB you can write to different SSDs before the spare area is exhausted. I cannot find a link to this test right now, you can search for it on the anandtech site.
I can, however, give you this quote from anandtech:
"Despite having a far more limited lifespan compared to its 2bpc MLC brethren, the TLC NAND Samsung used in its 840 turned out to be quite reliable. Even our own aggressive estimates pegged typical client write endurance on the 840 at more than 11 years for the 128GB model."
Check out their review, it also has a page dedicated to endurance: http://www.anandtech.com/show/7173/samsung-ssd-840-evo-review-120gb-250gb-500gb-750gb-1tb-models-tested
EDIT: Here, the endurance aspect of the drives caught my attention and found this endurance test for the Kingston SSD: http://ssdendurancetest.com/ssd-endurance-test-report/Kingston-SSDNow-V300-60. The author said that the Kingston was the first SSD to actually fail during their tests.
And here is the EVO test: http://ssdendurancetest.com/ssd-endurance-test-report/Samsung-840-EVO-120. The EVO test is ongoing, and was being performed while the Kingston failed.
Is this an isolated accident? Are the authors not to be trusted? You be the judge of that.