Except you have to consider a few things here. If was assume that Samsung's controller is capable of even wear leveling and the expected life span of TLC flash (1000 writes), then you can be expected to write 1PB of data before the SSD starts to croak completely.
Not only that, did you even read the end? Anand recommends it completely and wouldn't even mind using it as his primary storage. To quote:
I'd have no issues with one of these drives in my system even as primary storage. The performance story is really good (particularly with the larger capacities), performance consistency out of the box is ok (and gets better if you can leave more free space on the drive) and you've got Samsung's firmware expertise supporting you along the way as well.
The question of an SSD's lifespan is how much data per day are you writing
? If you are routinely making 1TB writes a day, then sure, TLC flash is probably not the best choice of flash type since the life span is less than 3 years. If at most you're just doing hundreds of gigabytes a day (we'll just say 300GB), then you're looking at an expected lifespan of 9 years. But I'm also finding this setup strange. Why use an SSD to record your footage? If you're recording at something at like 36Mbps (Blu-Ray quality), then a hard drive is more than capable of recording this with room to spare doing other things. With the amount you paid for the 1TB 840 Evo, you could've easily purchased 4 4TB HDDs, and probably could get a bit of a boost with a RAID 1+0 or two RAID 1 arrays.
Also notice that MPC doesn't do any power supply reviews. Among other things. But that's fine. I enjoy their content and if I find them lacking, I go somewhere else. But I go somewhere else anyway to get third and fourth opinions.