Product has worked well so far. Original lasted four years, so we hope to get at least that much use out of this one. We'll be very careful with the charging routine.
These batteries are so expensive that two of them would equal the price of a new lawnmower. In this case, the shipping was free (and prompt). If we'd had to pay for shipping of this fairly heavy object, the extra cost might have tipped the balance in favour of junking the lawnmower. Fortunately. we didn't have to do that.
The lawnmower itself has served our needs well, as we only have a small lawn, and a larger, more expensive lawnmower would be overkill.