Product review (2 stars): Early replacement
Purchased two-pack from Amazon.com.  Used both units.
I expected a total of 12 months before replacement...had to
replace in 8.5 months....29% less usage...if you use current
Amazon price of a two-pack at $65.98 x 1.29 = $85.11/2 = $45.55 each.
Very close to Best Buy's OEM price.