Here's my hot take:
DISRUPT_SPAWN - Seems weak, but I say that with low confidence. Probably you have to get level 4 or 5 on this or not bother at all.
DISRUPT_TERMINAL - Obviously powerful
EXTEND_SOURCE - Gives me free energy. Do I need that? I don't understand why it has a high level cap. Seems weak. Possibly cheaper to just sell the ops for credits and buy energy (especially if you consider CPU).
OPERATE_MINERAL - Underwhelming. I'm not tying up a level 23 creep to double the mineral output of one source. Ever. Even at level 5. Economically more efficient to generate ops and sell them with a bunch of smaller PCs.
OPERATE_LAB - Seems pointless. I will never use this. For it to be good, the effect would need to last for enough ticks that I could boost several lab clusters with the same PC. Even then, I do not think the effect would be worth the CPU required to move that PC around to each cluster.
SHIELD - Probably some good tricks you can do with this. Jury is out.
OPERATE_STORAGE - I was pretty excited about this one, mostly for temple rooms. Unlike OPERATE_LAB the effect lasts long enough that I can buff several rooms with the same PC, so it can't be too bad.
OPERATE_SPAWN - Seems weak, especially at low levels. I could see there being some edge case uses around bringing up RCL6 rooms to RCL7 faster. I find that I am almost never spawn-rate limited in Screeps, so this is a solution to a problem I don't have. If the effect lasted longer it would be more useful.
DISRUPT_SOURCE - Utterly pointless. Only useful on attack. Only useful when attacking someone who only has 2-3 rooms (will not effect bigger players who can terminal in resources). Only useful when attacking someone with no credits. Basically it's only useful .00001% of the time and even then it does not unlock any new capability, since I can crush that person anyways. For this to be good, you need to increase the radius of effect to be 3x3 rooms at level 2-3 and 5x5 rooms at level 4-5.
OPERATE_TOWER - Not sure about this one. If I can always scout enough to make sure my operate_tower PC is in whatever room is being attacked, then it seems like it could be good. I think probably most players don't get attacked enough to take this skill over one that provides constant benefit (as opposed to situational). I think if I take the situational skill, it needs to really pay off in that situation. Not sure this rises to that bar.
DISRUPT_TOWER - If it lets me clear RCL8 rooms with unboosted creeps, then this might be worth it. Haven't done the math, so I'm not sure. Otherwise I'd rather generate ops, sell the ops, and buy the T3 boosts I need to crack the room instead, which is a lot less situational. The problem with this is I need to be attacking all the time to get value. In general, I'm not.
OPERATE_OBSERVER - Would like to understand the use case for this. If it would let me scan other shards, then that might be a weird useful edge case. It sounds useless to me and I don't know that I will ever take this. I think it would be more useful if it upgraded my ability to get event-based intel. I.e. my observer raises events when NPCs, invaders, or other players enter my zone of control. This would be a CPU improvement over active scanning. Then I might take it. As designed, I don't think anyone will ever get levels 2-5 in this skill.
OPERATE_EXTENSION - Maybe useful with OPERATE_SPAWN? Otherwise I'm never limited by how fast I can refill my extensions. It's not an exciting skill. For this to be exciting, a single low-level PC would have to be able to replace all of my extension refillers. Then maybe I could save some CPU if I had a bunch of these PCs in a bunch of rooms. Basically, if this is only useful when I'm being attacked, then it's a bad skill. As it is, it's probably more CPU efficient to sell ops, buy energy, and turn off some remote mines if what I want to get is CPU.
OPERATE_TERMINAL - A skill that saves a little energy. That's what no one needs. Even if this made transfers free across any distance, I probably wouldn't take it, although it would at least be useful to some players if that was the case. To take advantage of this skill, I now need to queue up all my future transfers in a way that lets one PC do a circuit around a bunch of cities that want to send materials. Even just the CPU cost of running that PC around doing that is not worth the energy I'm saving, and that is assuming that those transfers exist often enough to get a good duty cycle.
TLDR
I'm probably only going to use powers that:
- Unlock new capabilities for my empire (i.e. DISRUPT_TERMINAL)
- Can create efficiency constantly (OPERATE_STORAGE?)
I'm probably never going to use powers that:
- Provide marginal or sporadic benefit (ex marginal: OPERATE_LAB. ex sporadic: OPERATE_TOWER)
- On the attack are situational but not significantly superior to regular T3 boosted creeps (lol at DISRUPT_SOURCE)