I have most of the 18V LXT tools and I would highly recommend them. I am now a retired part time renovator/DIYer and I have yet to throw out any of my 18V, 3ah batteries...the oldest is about 8 years old
I have not experienced any of the battery problems that have been reported...I have at least 10 batteries, and I do recharge them usually right after they have been discharged. Amazon's 2 pack saves you between $30 and $40 over the prices usually found in the major tool and lumber stores.
I wonder if the poor reviews are really about the non lithium ion batteries which seldom last 4 years with any runtime...I have several 9V nicad cordless tools, so I speak from experience.
Makita's 18V LXT system is the best cordless tool system that I've ever used.