Many options will be considered for the cloak. Understand cloak will be a WiP. So dont expect it to be "perfect" when 0.4E hits the web. We are going to try the drain antimatter option first, and see how that goes. The lump sum option does have merit, and we will consider that if the over time drain doesnt work out like we plan. The most important thing is we do NOT want cloak to stay on constantly, because it will be abused beyond belief. If i can think it someone else will do it. It would be pretty annoying if someone just sat cloaked in your grav well taunting you, and you couldnt do anything about it (unless you had a de-cloaker). Lets see how this works out before we make structures able to de-cloak ships. The Sins AI still does some very stupid things no matter how much you micro. Like make b-lines for the nearest asteroid, or building only to get stuck. With dynamic movement they now make b-lines for the planet only to get stuck :/
The drain over time option uses quite a bit of AM. Plus it ensures someone doesnt cloak then sit still in a grav well cloaked, because sooner, or later the AM will run dry, and he is forced to de-cloak. This means attacks will have to be timed, and managed very carefully. I also want to avoid the decloak, shoot, re-cloak.. rinse and repeat till ship/structure is dead without chance to retaliate.
For the Romulans i picture this scenario. Just before an attack fleet cloaks, then jumps they arrive in Feds grav well. Feds say "oh shit! Romulans are here, and we cant get a lock". Feds spearhead a decloaker if they have one, and pick off the few ships it can decloak. Rommies de-cloak, and chaos begins.
For the Klingons i picture this.. The Klingon cloak is not as advanced as the Romulan cloak. Klingon cloak will use more AM than a Romulan cloak. Not all klingon ships will have cloak. Klingons usually decloak to herald an attack as soon as they arrive in a grav well. If they even cloak at all before the battle. They think sneak attacks are a dishonorable tactic. However they will cloak to disengage, and retreat from a battle going very wrong. How you use the cloak it is up to you.
IMO the series and movies broke their own rules (which were being made up as they went along) with the Klingons. For example Chang's fire while cloaked B'rel... OK. ANY Klingon Warrior with a sense of Honor wouldnt even board that ship let alone fight in it. Did Chang like Duras have no honor? We know he went rogue, but he fought like a Romulan free from retribution hidden in the shadows. That is not the Klingon way. A true warrior would have shown himself, and if the battle went badly there is no dishonor in retreat as long as it serves a greater purpose.