I build outposts with towers because they let me connect resources. I consider this at the time I place the outpost itself.

I don't build the one that gives food, however I changed my copy to give +2 instead of +1, which makes them better. I also tried making them +2 gildar however it never paid off, and growth was better.

The 2 buildings that give 25% attack/defense need changed, if they gave 33% they would be great (not for me, for the AI when defending itself against each other, and to help vs monsters as a reward for having the outpost there). Otherwise, they should be combined into one building that gives 25% attack and defense inside borders.

The Stable is wonderful, it allows me mobility on large maps, especially Anthys.

Reducing tactical spells is useful during defense and on offense you can sack an enemy monolith or outpost and rush buy this improvement. You can also buy an Arcane Monolith or settle a pioneer on the go, and rush buy it to have reduced tactical spellcasting everywhere except enemy borders.

I would like an improvement that gives 2 militia if attacked (like a city). Enabling this auto-protect without garrison would make players + AI have another defense from each other and monsters. This isn't overpowered because the units couldn't leave the tile to defend a nearby tile in it's zone, it can only protect itself.

I never use Caltrops because it comes too late. If it came as one of the first 3 or so improvements, I would definitely use it.

Warden conflicts with any ability which is good for the tower (except stale) 80% of the time. However, it does give a choice because you probably don't plan on building the others if you do build a warden.

Something (not) funny is happening. Comparing my development vs AI development (Huge Map), the AI either spams early cities and wakes up all the monsters or fails to expand at all and stays at 20 points or less all game. There are large barren swaths of land all over the place, and i spend so much energy defending myself (Porcipinee, or any non-fire user) that I don't have time for pioneers. Instead, I send out my troops plopping Arcane Monoliths all over the place. By the time I have 5 cities (1 Fortress, 2 City, 2 Conclave is my norm), I have 12 towers all over the place and the AI has super swarmed.

What balances me is high frequency of events, rampaging monsters, distance between each target until it expands close to me and the need to acquire resources and empty a spot quickly.

Mid-Late game around turn 200, I have around 1/5 of the map covered in outposts and 5 cities or less. The rest of my cities are taken from AI.

In the game I won with Porcipinee, fortresses were my lifeblood. Eventually the areas I had popped forts around to capture and connect a path of resources, I found areas I could settle with monsters in my killing range. I had occasional setbacks with quests that caused monsters to appear inside of my undefended fortress zone on SE Anthys (West Continent). Skeletons raged throughout my land and forced me to direct my rear armies to the south mid-invasion of Yithril to the north. I had taken 2 cities, and was going to swap drained units for fresh ones, but was forced to accept the loss of those 2 cities to get down there and repair the damage. This was a fun, unexpected challenge because it effected every player, and the army coming at the cities I captured were distracted by skeletons for a few turns which gave me time to get the gold to buy peace. Right as my army mopped up the last skeleton south, a blood moon came and the "story unfolded".

In the end, I was able to win by conquest. I had a late-game explosion in power which allowed me to demand and receive surrenders 10 or so turns into a war.

I also found a bug: You can make an AI pay for peace then on the same turn, declare war and if you drain their coffers you can make them surrender. The AI placement of outposts was good but they weren't able to make good build queues to consider the importance of a given outpost or priority to its defense.

I would like to use them, but the amount of city construction time has just never been worth it. Too high cost for the benefits.

Use them all the time when playing with Arcane Monolith spell.  Good for resource grab, linking towns to lower unrest, stable upgrade for moving swiftly within territory.  Agree with ElenaAhova that if SD decides to eliminate, please keep them as an option that could be enabled.

This.  The city production queue is too precious to be used on the current outpost upgrades. 

You could make the upgrades instant, but cost resources (money for outpost, crystals for abbey, metal for armory, horses for stables, etc) instead of production. Just a suggestion.

It seems pretty clear that there are at least two opinions about this. Some people consider city build queue too precious to use it on outpost upgrades but some other people think it's worth. To me it looks like there is no obvious choice and it depends more on playstiles, which turns outposts into an strategic choice.

Only attack/defense upgrade on mountain passes to halt enemy advance.

Biggest issue is they use queue in nearest town and almost always there is something better to be built there. Except those 2 upgrades.

Hightower only.  Even that only where I need it.

As a former Civ IV player who is still pretty new to FE the City/Outpost thing was the most confusing part of the game early on.

I used them in FE but the population cost made it so I didn't really use them in LH. I also think that outposts should be changed so that they get there own build queue, and cover four squares in any direction, but have a gold maintenance, or maybe even lowers growth in the connected city. The bonuses would make the population cost worth it, and the maintenance would balance them.

Also it would be cool if they spawned a group of warriors or archers every once in a while...

I very often use outposts, mostly High Tower and faster travel, then growth. I've found the Warden to be rather lackluster and only prevents the lowest level of creatures from roaming around. If I'm going to have a patrol out stomping the bigger things down, then I might as well use that same patrol to rid myself of the pests.

DevildogFF, the answer to your question can be found upon launching LH. It tells you at the bottom of the beta loading screen the answer you seek.

I tend to crank up the world difficulty so I almost always build at least the Warden to keep some wondering monsters out. Other than that it depends. Sometimes it's worth extending the borders to grab another resource. When using the super army strat if I have a couple close together I'll build the extra movement, def, attack and 1/2 mana upgrades. Not sure if they actually apply to quest zones even if they are in the area, never bothered to truly pay attention, just did it off assumption.

At best I'd say they usually have minimal impact on the game, more a quality of life thing.

I use upgrades on outpost depending on their location. If there is a border town, you may consider building outpost right next to it and then upgrade defensive bonuses on it to help in battles. Also, high tower upgrade helps reach further with your border and get an additional resource(s) or, like in my last game, connect your isolated city that was just one tile outside your borders. I find upgrades useful addition to outposts. Not sure if AI ever uses them though.

I have only recently found out they can be upgraded and loved it, but im not seeing the bonuses working....ie adding stables doesnt seem to increase my movement value while in the area...unless its not adjusting the number I see for my movement, but is letting me move more.  Will do more testing on that.  I love the fact that you added this in though as I play on ravaged worlds, and being able to put outposts at resources is huge.  Maybe not so on a lush world where you can place cities like crazy, but on ravaged I love it.