Google "optimajim + sorry" for some interesting reading.
This thread is particularly entertaining.
http://www.pirate4x4.com/forum/electrical-wiring/913442-batteries-optima-alternatives.html
In a nutshell: they're garbage and no longer as good as they used to be.
I prefer stuff by East Penn Manufacturing... Made in USA. The Deka Intimidator would be the AGM equivalent of a red or yellow top.
Read what you can and form your own opinion. A friends large fleet of cars(modern DD stuff, old 4x4s, his lawn service trucks, some old British sports cars, a Trans-Am, etc. Little bit of everything) having over a dozen dead red tops over a 2 year span convinced me something went downhill. All replaced with normal lead acid or Deka Intimidators for the more abused stuff(winch on Jeeps, etc) and never an issue again.
They were dying every 9mo to 1.5 years or so.
Carquest "NGT Extreme" batteries are rebadged Deka Intimidators.
Tip: bring a multimeter with you to check any battery you're buying in a store. They lose capacity when they discharge for long periods of time.
I won't buy one if its below 12.5v... Even then its a good idea to charge it before use(NOT throw in car and drive).