Optimas have more exposure to air (So they cool faster) and less capacity than other batteries.
Still, in the larger scheme of things, that is not a big difference in charge speed.
PLUS, imaging a 700 amp charger.. WOW. That is like 9 times the converter I have here. AND it would total my 30 amp shore line. It would major damage to the remaining power on my 50 amp cord in fact. Any converter over 100 amps is actually impractical on a 30 amp rig, or 200 on a 50. You simply do not have that much INCOMING power.