Samsung provides 3 years warranty, and the 840 delivers good performance for a really good price, also write performance is ok, not the best but sufficient.
I would go with the Samsung.
The 512Gb Samsung 830 excedes my budget. Mushkin also provides a 3 year warranty.
check the 830 ... better than 840...not 840 pro
Also above the set budget.
Any other suggestions or which of the two drives is better?