To Brandon, I would watch out for chargers like these because my brother has a similar type where he can switch between the 6A and 2A rating. These chargers work on slowly tapering the current off as the battery nears the 14.40V state at which it is considered to be fully charged. His charger puts out only 13.57V at the 2A setting undercharging the battery, at the 6A settings the output is 15.77V which overcharges the battery. I do not know personally about this particular charger, but make sure that is will cut out at the 14.40v rate.
I personally have the Yuasa 1.5A charger which I have verified that it supplies a constant current of 1.5A up to the 14.40V when it cuts off. Mine actually cuts off at the 14.32V stage, but that is more than close enough.
The slow charge takes care of a couple of things, it gives the plates ample time to convert SO4 back to active electrolyte, and ensures that if a battery has been partially charged thus creating higher internal resistance, that it will not generate heat which will further corrode the plates.
I personally have an Exide Orbital similar to your Optima, even though many here say that regular Exides are very bad this one (manufactured in Spain) just keeps going and going (6 years). Had it discharged several tiles to 0, just a couple of weeks ago I left my console light on for the entire 3 day weekend and the car fired right back up without any problems. I have used the 1.5A charger to bring it back to life, took as much as 2 days of continuous charging at 1.5A to bring it back to life.
If I cannot take a battery out of the car I simply hook up the charger over night and let it run. If in the morning I do not have a full battery charge I repeat the same process the next night until the charger states that a battery is at full charge.
Your situation: start the engine, alternator sends a high current to the battery, the plates which have some SO4 crystals (undercharged battery) create internal resistance which causes the voltage on the battery jump to 14.40V, alternator thinks that the battery is charged and tapers off the voltage not knowing that the battery is undercharged. Not all the SO4 crystals are converted back to active electrolyte, SO4 crystals harden over time causing even greater internal resistance, higher internal resistance will cause further undercharging and generate more heat under high current which will damage the plates.
If SO4 crystals are allowed to harden (discharged state for a long time) they expand by nature, they force the plate to expand as well and since the plate it pressed into a battery under pressure to avoid vibration the plate starts to buckle shedding off these crystals which cannot be converted back to H2SO4. Then eventually undercharged battery + high internal resistance (low current flow) + damaged plates will cause harder + slower starts.