I've been reading up about this topic mainly because I was looking to purchase a Samsung 840Pro and wanted to know what was different between the SSD's. Most SSD drives use 2 nand controller chips for data storage and recovery. The Pro version uses 3 nand controller chips. You mention TLC which has a lower read and write life expectancy. I believe that you can get around this if you create a Ramdrive and direct all the temp files and intensive read and writes to run on the Ramdrive. That will decrease the actual read and writes to the drive itself and thereby improve it's life expectancy. That may be a way to make TLC drives attractive to buyers if you incorporate the Ramdisk software with the purchase of these drives.
I think you need to go back and start reading again. I haven't a clue what you're on about with 2 NAND controller chips vs 3 NAND controller chips. Both the 840 and the 840 Pro use the same design with a single controller. the 840 Pro uses MLC NAND (2-bit per cell) and the 840 uses TLC NAND (3-bit per cell).
Unless you are a very heavy write biased user or use professional level software you will not wear out a TLC based drive within a sensible time frame (maybe 5 years).
If you are a very heavy user then purchase an MLC based drive, where again you are unlikely to wear it out in a sensible time.