If it were me, I would go with the Samsung. I have 2 256GB 840 Pros (in 2 systems) and couldn't be happier with the performance. Samsung generally makes excellent products. I (and many others) recommend them as a company often.
I the case of these 2, from a performance standpoint, I also believe the Samsung will perform better of the 2. An example of the performance can be found here:http://www.anandtech.com/show/6337/samsung-ssd-840-250gb-review/
Look at the benchmarks where both models you are considering are listed.