The price is pretty good, lowest I've seen on this drive with the kit. However, I too am a bit nervous about the 840 series and it's TLC versus MLC. TLC is estimated to last 1/3 as long as MLC.
Sorry for quoting myself but:
All the reviews that I've seen comparing the 830, 840 and 840 Pro have run limited endurance tests, gone by what the manufacturer said, and then extrapolated out an expected
lifespan of the drives.
And frankly, the lowest lifespan I've seen under normal usage conditions for the 840 is 7 years
which I'll grant isn't the 830's 21 years, but do you honestly think you are going to be using the same hard drive in 7 years?
Not to mention that isn't the entire story because that 7 years is how long it would take to wear out the NAND. That doesn't take into account any DSP technology that the drive might have, which could at least double that lifespan, if not significantly more than that.
Which means that with wear leveling you would have to write 275TB of data to this drive before it hit that threshold.
Is the 840 the successor to the 830? No it isn't, that is what the 840 Pro is for. Does that mean that the 840 is a bad drive? Hell no, it is faster and more capable then many drives out there and for its price point it is really the best deal out there.
Again, it depends on what you expect to be using the SSD for.