If you don't think that giving full vision to all neighbouring planets is too strong (which it is - much too strong) then fine, go with the Station thing. It's easy. It's simple. It requires no thought or action on the part of the player. ...All entirely aside from the issue of it being way too strong, of course.
You keep saying that, but there is no argument at all about why it's "too strong", or why you call a choice. What I see in the "stations give vision" idea is a weak capacity which leaves room for AI ambushes (explained before in the thread), and how I see in most other idea is "creating chores".
Let me explain:
About the "too strong part", if neighboring stations gave vision, the average number of planets seen in my games at late game stage seems to be about 35 to 40.
At the same point in time in AI War I, I'd have COMPLETE vision on the map. Or in any "node based" (like sins of a solar empire) or grand strategy games (endless series, all moo clones...), for that matter. In a lot of them, I'd have either complete or near complete vision on the map near mid-game, with little to no actions on my part, just by playing. The only strategy games where I typically don't have that level of coverage would be starcraft-clones or or warcraft-clones. In those, however, early to mid game, I know what is on chokepoints and bases. When I don't have vision, it's because the enemy is on this particular point and the game strategy IS about hiding what the enemy does and making the player do as many actions in a minute as possible. Resending stuff in this kind of game is ok, because the game lasts for 20 minutes or so. That ain't AI War's style, so I'm going to base the first types of games as standard.
In conclusion, what you call "too strong" (free vision on stations) would still requires 300 to 700 hacking point to reach what I see being the "standard". Complete or near complete vision on the map is strong. Less than half of that ? Nope. And, I'm ok with having bigger FoW in AI War. Just not to the point of gambling when moving to neighbour planets.
Another point is, you're competing with "going back to your fleets to send one ship on a neighbour planet" or "sending your transport back and forth, again and again", for vision. That is in the game, and ain't going to move. So, let's compare the propositions with what you call "with choices" with that.
Basically there is 2 main criterias in what is proposed. Either you can switch where you're looking or not, and they can have hacking point, or not.
If they enable switching, the BEST use of the system consist in going back to whatever causes the vision to be active every X amount of time (with X as small as possible) and switch it again, and again, and again. That's whether it has a hack cost or not. That's a chore when you have to do it for dozen of hours (typical length of a game)
If you don't enable the player to switch, first, it's going to piss some players of because of misclicks and specific situations like "but what if I conquer planets where I had vision, shouldn't I be refunded ?". Which ain't that awesome in the first place, but then you have to consider something else. Its costs.
If, for example, you make the hacking cost low enough, like 1 for neighbouring stations, that's giving the player a choice between wasting hacking points (the NOOB way) OR sending a ship from his fleet every 30 seconds to die for vision (the "PRO", but insanely repetitive, way). Or sending a transport back and forth. You're back to the chore part.
If you don't add an hacking cost, but limit the number of places you can look at, then, you're basically forcing the player to send ships from their fleets every X time for vision where you "chose" not to look. And back to the chore part.
In a game like AI War... There is absolutely no "finesse" in any of this. To me, those ain't choices, they're chores. Because it's brute-force and repetitive. Currently, my late games have all past 8-10 hours. Doing repetitive actions for that long is making me dislike the game. The worst thing is that proposed actions mechanics often LOSE to "sending ships from your troops to die" in term of how interesting they are. And this mechanic makes sense in a game that lasts for 20 minutes like starcraft. Not in long games.
Last point, the number of things that a player can keep track of is limited. Scouting for regular stuff is BORING. I've got nothing against adding new mechanics into the game, but, at least make them interesting ones. If you add this to the game, you reduce the "brain space" available for a new mechanic, for something more interesting.
The reason I like "neighboring vision on stations" is because it's "brain dead" level of complexity. And, as far as I know, most similar games to AI War have this built-in - it's like the standard FoW in all games with nodes, at least 1 node of vision, and usually 3-4 at end-game. I don't remember people calling it OP. What I do remember, however, are threads about people making the scout mechanic from AI War less grindy (and similar threads about similar mechanics in other games, like scouting in the dominions series...).