I have owned several sets of their batteries. I ended up returning a few the first couple years I used them and it might have been partly my fault then because I didnt take care of them like I should, I didnt know any better. Now I baby my batteries and I get about a year out of them. Keep in mind that I use a jon boat with trolling motor as my only power and they get ran down several times a week. I think thats about all you can expect out of a $100 battery. I did get a dud back in January but they tested it and said it was bad and replaced it. I was sure their "tester machine" was rigged to say all batteries were "good" but I was wrong. The battery I use is the maxx and it cost about $100. It says 18 Month free replacement, but I have never had a battery that lasted that long the way I use them, I dont expect one too. A hundred bucks every year or so is a small expense compared to spending that every time somebody gasses up the bass boat.
Overall, Im happy with them.