Yes they are for all intents and purposes for the general user like the OP, myself and the vast majority of people.
This
comparison review of the 840 / 840 Pro 256GB details the differences between them. Yes there are a few differences, such as more durable NAND and additional over-provisioning space. However with a cost difference, the average user is not going to use the Pro in such a way as to justify the extra cost over the non-Pro version.
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I kept my answer above generic because I didn't feel it was necessary to detail the minor, everyday differences which are inconsequential for most of us.
The URL to Anandtech that
Weaselboy referenced is also a good place to get details on the NAND. Plus we have a dedicated thread to the
840/840 Pro here with lots of details on them.
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Writing 10GiB per day with a write amplification of 10x to the non-pro version will last
at least 7 years.