I have found most every bad review this company has is not because they did anything wrong, but because people did not read the terms of their warranty, or did not pay for coverage because they 'expected' certain life out of the battery.
They are amazing, have worked on my car before and I have been with them for years, I also have friends that are driving with their batteries and no one has a bad word to say.
Recommendation: Ignore the bad reviews, just understand your warranty terms!