I can't speak to the science of why an optima is better or worse, AGM batteries have been around a while now and they are superior, I use them in my motorcycles and most batteries sold now are agm, so its not something new and special.
Optima is just a line of Interstate batteries, its made by the same people as any battery marked interstate. I spoke with an interstate rep a few times when I was having my optima issues and he told me, if you want AGM go with the mt7 series, saldy they dont have a group 27 but the 34 will fit and I have used them, I have better luck with them than the optimas which seem to be hit or miss. Some people love them some people hate them.
Now to say they are failing because of misuse, why did the battery that replaced it last for 6 years so far? The first one I had was in a plow truck that only got started in the snow, I had to get in the habit of taking a jump box with me, and there was no rhyme or reason as to why it wouldn't crank, sometimes it was only off for a couple days and not enough to start it, sometimes it was it was off a month and it would crank right up, sometimes I would shut it off and go to start it right back up and nothing at all.. I replaced it with a megatron and NEVER had another issue, not once, that truck sat there for 9 months with out touching the key, then on a 9 degree snow covered day I go clear it off, turn the key and BANG starts right up...
That optima was replaced for free, but that was it, I put it in one of my work trucks and 6 months later it wouldnt hold a charge, no second warranty, just replace it once.... I recycled it. I had a prostreet car that had a shitty charging system, ran off of the driveshaft, battery in the rear seat between the roll bar. I tried another optima, supposedly the best battery made, it was not up to the task, never had enough charge to start the next day, no big deal I put it on the shelf and put a heavy battery back in, again no issues, I sold that car after owning it for less than a year but never had to jump it again after I put the heavy battery in...
The optima gets taken off the shelf and put in a toyota tacoma, brand new truck but I added an electric plow so I figured the optima would do better and I had it there, plus the battery that came with the yoda was tiny, like 4 9v's taped together...
NOPE, no good, ended up stuck again!!!! Didnt even give it a second chance, put the yoda battery back in and have yet to have a problem.
so in my experience they suck. Not only that but they are ugly, in a hot rod or classic I dont want this futuristic red or yellow top in there, a decent battery that looks like a battery is much nicer... Maybe they look ok in a pro touring car, but besides that I prefer the std square battery.
I had a conversation with an interstate dealer, he told me you want proof the optimas had problems, go to amazon and read the negative reviews, sure a lot of positive but read the negatives, the batteries marked INTERSTATE are made in the USA, the ones marked OPTIMA are made in mexico, that could have something to do with it...
SO IMO if you want agm, get an mt5 or mt7, stay away from the optimas, I wish anyone with them one luck, and I hope they last forever, but in my experience, having owned $1000 worth of them and not having 1 great experience, I will spend my money else where...
heres interstates line up, you can see they put optima at the bottom
http://www.interstatebatteries.com/m/category/car-and-truck-batteries/
