i'll just add here a few things:
the SLC memory only modulates between written and unwritten.
for one, an SLC usually capable of x10 writes vs the MLC (~100k vs ~10k), so, even if the drive is using 2 cycles per write, it still has much longer potential life.
an SSD erases a full block before rewriting to it, it doesn't erase single cells,
it cannot of course just paste the data, as some cells would still contain the eldest one.
it must then erase a full block and rewrite it and u have write amplification added to it.
it doesn't seem to work that way as bit-tech described, u should read the SSD relapse at AT to figure it.
erasing each cell separately, doesn't seem right, it isn't DRAM.

as for TR, these drives aren't exactly replaced every month, or even year, they're quite resilient, of course depending on the controller and quality of the product.
again, have a look at AT article, he got quite in dept explanations at that,
(havn't had the time opportunity yet to unfold this technology entirely).

it's really not about which drive is better, it's more about what u need.
SLC's are generally faster, more robust, and so expensive.
if u don't mind losing a bit of speed, u shouldn't be losing any from using any decent MLC.

SLC basically, are less for mainstream users and more for demanding work load enterprise use, where drive robustness is really important as it's life time, price is less worrying and speed is always a benefit.