Here is the list in Full:

Level 3 City Improvements:

Conclave (Level 3)

• +1 Essence
•  +20% Research when Idle
• +10% Resarch and Scrolls

Town (Level 3)

• +50% Gildar when idle
• +1 Gildar per grain -2 food per grain
• +1 HP For Trained Units Per Grain (in this city)

Fortress (Level 3)

• +5 Initiative for Stationed Units
•  -10% Unrest
•  +.5 Growth, Heals 10 Hit Points Per Season to Stationed Units

Level 4 City Improvements:

Conclave (Level 4)

• +10% Research and +25% xp for trained units in all cities (currently bugged)
• +1 Crystal
• +1 Fire Power +3 Mana +3 Maintenance

Fortress (Level 4)

• Impulsive granted to trained units (in this city)
•  -10% Unrest in all cities -1 growth
•  +1 Metal

Town (Level 4)

• +3 Growth +10% Unrest
• +1 Prestige
• +1 Influence +1 Maintenance

Level 5 City Improvements:

Conclave (Level 5)

• +1 Water Power -30% Unrest
• Unrest does not affect research
• +3 Maintenance +10 Spell Resist for units built in this city and city is immune to enemy spells

Town (Level 5)

• +1% Interest on total gildar
• +2 Production per material in all cities
• +1 Gildar per material

Fortress (Level 5)

• -30 Unrest in all Cities
• +1 Earth power -50% Armor Production Costs
• +1 Attack +3 HP For units built in this city

Balance Issues

Conclave (Level 3)

• The plus 1 essence from level 3 compared to 10% research or 20% research when idle is a no-brainer. If for some reason you really want scrolls, the +10% research trumps the +20% research when idle by a large margin given how long it takes to build structures. A much as I love the bonus essence this ability is probably OP for a level 3 city and should be moved up a tier (or two). +25% xp to all trained units in all cities would be a decent replacement. The bonus to research should be an actual number (+1 per essence). The idle bonus should be replaced with something else (+1 mana per essence would be good)

Town (Level 3)

• The +50% idle bonus is not very intuitive, especiallly since you won't likely see it's benefit until the city is much larger, making it a poor (albeit good for later) level 3 choice. This should instead be replaced with +1 Prestige from level 4. The +1 gildar per grain is nice. +1 Hp per grain for trained units in this city is silly. The focus should be on fortresses producing units. And on that note the bonus should be +1 HP For all units trained everwhere.

Fortress (Level 3)

• The +5 initiative to stationed units should probably be +1 Initiative to trained units (so the choice is growth, production, unit strength)

Conclave (Level 4)

• If the academy gave that bonus to all cities it would be a good choice. (probably +15% research and no experience bonus would be better) The +1 Crystal is obviously a carry over from the last version when crystal was scarce. The bonus here should be +4 (as if you had a max level deposit). The Fire academy thing is broken for two reasons: 1. You might not have any fire mages, or 2. You have fire mages and they are suddenly stupid OP. This would be a good spot for +1 Essence.

Fortress (Level 4)

• For the same reasons as above this should be +4 Metal, or +1 material

Town (Level 4)

• As mentioned above, swap out the +1 prestige for the +50% gildar bonus when idle. The slums is fine, though I'm not really a fan of the +1 Influence. I just don't like influence though so I could be biased here.

Conclave (Level 5)

• So many things are wrong with this it's hard to know where to start... The +1 water power has the same problem as fire power and the -30% unrest is lackluster given the bonus unrest that conclaves already get from essence buildings and the No penalty to research is pointless given the choice above and the already low unrest. +10 Spell resist seems to be a carry over when Spell resist numbers were low. Ahem, the recomendations here would be +20% crystal and mana generation, +15 Spell resist for all units trained everywhere and city immune to enemy spells, and +50% Research bonus when Idle.

Town (Level 5)

• The bonus on interest is so utterly broken.. This should instead be +2% bonus to gildar from population (in this city). Consequently the +1 gildar from materials is never going to be better, and should instead be replaced with +.5 grain to fortresses. I really like the +2 production per material thingy.

Fortress (Level 5)

• -30% Unrest to all cities is too high, even given how rare level 5 fortress are. This should either be -15% or -20% The earth power has the same issue as all the 'power buildings' and would probably be better as +1 warg/horse resource.

Finally as a side note, Towns should gain +1 grain in addition to the +1 border range. And the alchemy lab should be 1 per faction!!