I've read both ways on Optima batteries, bad and good reviews. I bought a Red top for the 'stang 4 years ago and got a charger deal with it. Can't remember if the charger was free or at a steep discount, but the red top came with the Optima 400 charger (smaller 4A charger). Normally the 400 is a $100+ charger but all the functions it has are really worth the money. There are plenty of chargers on the market that are different/better/more expensive/do more but I'm really happy with the Optima product so far. I keep the Red top on the optima charger when I hit the road for work. The car sits for months, most recently sat for 6 months. The charger maintains/cycles the battery during long term storage, and I don't have to babysit it or remove it from the car. It's fused in-line between the charger and battery terminal and has temperature correction built in. I set it and forget it. Car never felt weak turning over since the Red Top.
As for the OEM, mine only last 2 years in the Vegas heat. I tried to get Ford to own it, but the vehicle was modified (nitrous system wiring under the hood) and you know how that one plays out. I replaced it with a Duralast Gold which made it 38 months (2 months after the 3 yr warranty LOL). That battery was apparently dying slowly and the combination of the shitty OEM alternator, I had a complete electrical failure while driving home one night. Alternator failed, and the battery lasted long enough to chug the car to an off-ramp and roll me into the middle of the ghetto. Never appreciated my CCW more 'til that night. Got the car towed home. Ordered a Police Interceptor Mitsubishi alternator (205Amp) and Optima had a deal going for buying a battery and getting a charger free, picked that up to. Never had another electrical issue with the car since. With the crown vic alternator I don't have to worry as much about short-tripping the car, as I know it can deliver power. Prior, I'm pretty sure the stock alternator wasn't keeping up. I feel better charging practices and a strong alternator have kept my Red Top alive and at peak performance this long.
Also, I have been using my optima charger on my '13 F250 OEM batteries for over 2 years. Every time I get back from the road, or every 3-4 months I throw the charger on the batteries and let it do its thing. Usually takes 12-14 hours to do both batteries. But they are the original factory batteries, making them 4-5 years old in a 6.7 diesel workhorse. Also have a stout aftermarket stereo in the truck. No light flicker with the bass either.