In my experience, the optimal ranges of EOs are short/pistol range, except for SELENA in which you need to be at point-blank range. Each cores have their own lock-on times and accuracies:
Lock-on times from shortest to longest:
CR-C98E2
C02-URANUS
CR-C89E
C01-GAEA
C05-SELENA
Accuracy from best to worst:
CR-C89E
C01-GAEA
C02-URANUS
CR-C98E2
C05-SELENA
The GAEA has decent accuracy and can be toggled on in rifle range, though it does have a delay before it actually fires. Keep this on whenever you are in range and has the surplus energy. It will reload 10 rounds at a time if left off for 6.5 seconds, toggling it on will however reset the timer. This is the core that can actually kill stuff on its own.
CR-C89E is good at breaking parts, and can keep up a steady flow of molten lead at whatever it is shooting at (EOs are rather rather sensitive when it comes to fighting multiple enemies and may not shoot at your primary target). While it cannot really kill ACs on its own, it increases one's damage output consistently.
C02-URANUS requires an entire AC built around it to work well; all those optional slots are there for the reason of enhancing this energy guzzling pea-shooter. This is the core that is most affected by optional parts: O05-HISTON will turn it into an actual machinegun, O06-PHAGE cuts down on the energy spent per round significantly, O04-GOLGI gives it a the much needed boost in firepower, and KISSYOH offsets its lack of AMS. However, the real power of this core stands in psychological warfare - inexperienced players will shy away when you get into their face guns blazing (I know I certainly did back in AC3 ). While it does reload quickly at about 1 round per second, it takes too long for it to finish loading all 100.
C-C98E2 is the premium damage racer. Pop it on at point-blank range and see it chip away at your opponent's AP. It is especially potent against grounded light-weights. Just try to make all the shots count by keeping in range.
C05-SELENA is the oddball of the bunch with its huge damage potential, on paper at least. Despite of its raw power, it locks on too slowly to be useful in a joust. Keep it on at short range, time the shots, and close distance right before it fires to make sure the shots connect. With its high usage drain and low accuracy, it is best used with a tank or a quad that can stun-lock an opponent with the LGL. It replenishes all 12 rounds when left off for 22.5 seconds.
Black Dragon is right in that EOs generate heat when used, they have a start-up heat like OBs when toggled, so it is best not to turn them on and off repeatedly when boosting. I will need to test GAEA and SELENA to see how long it takes for them to reload.
Edit: Corrected reload times, they are a lot faster than I thought but only seems slow because combat is so fast paced in LR.
Lock-on times from shortest to longest:
CR-C98E2
C02-URANUS
CR-C89E
C01-GAEA
C05-SELENA
Accuracy from best to worst:
CR-C89E
C01-GAEA
C02-URANUS
CR-C98E2
C05-SELENA
The GAEA has decent accuracy and can be toggled on in rifle range, though it does have a delay before it actually fires. Keep this on whenever you are in range and has the surplus energy. It will reload 10 rounds at a time if left off for 6.5 seconds, toggling it on will however reset the timer. This is the core that can actually kill stuff on its own.
CR-C89E is good at breaking parts, and can keep up a steady flow of molten lead at whatever it is shooting at (EOs are rather rather sensitive when it comes to fighting multiple enemies and may not shoot at your primary target). While it cannot really kill ACs on its own, it increases one's damage output consistently.
C02-URANUS requires an entire AC built around it to work well; all those optional slots are there for the reason of enhancing this energy guzzling pea-shooter. This is the core that is most affected by optional parts: O05-HISTON will turn it into an actual machinegun, O06-PHAGE cuts down on the energy spent per round significantly, O04-GOLGI gives it a the much needed boost in firepower, and KISSYOH offsets its lack of AMS. However, the real power of this core stands in psychological warfare - inexperienced players will shy away when you get into their face guns blazing (I know I certainly did back in AC3 ). While it does reload quickly at about 1 round per second, it takes too long for it to finish loading all 100.
C-C98E2 is the premium damage racer. Pop it on at point-blank range and see it chip away at your opponent's AP. It is especially potent against grounded light-weights. Just try to make all the shots count by keeping in range.
C05-SELENA is the oddball of the bunch with its huge damage potential, on paper at least. Despite of its raw power, it locks on too slowly to be useful in a joust. Keep it on at short range, time the shots, and close distance right before it fires to make sure the shots connect. With its high usage drain and low accuracy, it is best used with a tank or a quad that can stun-lock an opponent with the LGL. It replenishes all 12 rounds when left off for 22.5 seconds.
Black Dragon is right in that EOs generate heat when used, they have a start-up heat like OBs when toggled, so it is best not to turn them on and off repeatedly when boosting. I will need to test GAEA and SELENA to see how long it takes for them to reload.
Edit: Corrected reload times, they are a lot faster than I thought but only seems slow because combat is so fast paced in LR.