I actually like the current leveling pacing.

I'm ok with the pacing as well. Very few of the per-level benefits of leveling up are really game breaking, except the rate of hit point gain for groups of units.

If anything the benefits per level should tighten as they increase (for units, not champions) in level.

I think the amount of XP from level 8 to 20 needs to require alot more. I would be curious to find out exactly how the XP levels are tweaked. The Elemental Defs are not very explicit.

I like getting the less important levels quickly too. The early levels are fine to go fast. But there should be a pint where things slow down and leveling a unit becomes more difficult, but also alot more rewarding. Level 9 would be a decent plateau so that other heroes have a chance to catch up a bit and newly recruited level 9 heroes are still useful. I would then switch some of the lethal traits and other very powerful traits to be extremely common, but with a level 10 prereq. 

The speed at which units and champions level have nothing to do with the cities. The cities level based on population which grows by your prestige. How you could confuse the two is beyond me.

As for XP, I personally love my heroes leveling fast. That means even above lvl 8. Even by level 8 you have nothing really of note and you never reach the higher levels by end of the game which is silly. 

Sean, I have some idea into how the XP is done since I tweaked it in my own game.

I think the xp is currently too high, too, because it is no problem to reach level 15+ (medium map, standard settings) without the potential traits or the + 25 % xp spell. This makes the game much more difficult for the AI, because the player can level up faster (My Sovereign at turn 193: 17, AI Sovereign at turn 193: 10).

I don't think the problem lies with levelling speed, but what you gain from levelling...

I too think my sovereign gets a little too "automatic"... Although its abit hit and miss, you have to pick the traits that aren't rubbish

Sincerely
~ Kongdej

yeah they get easy exp too but... dont forget they come in play late, when you most likely kill high lvl stuff when they are low lvl

and partially i agree they have to catch up or they are useless

but still its too much

It's definitely too fast. Super-quick leveling coupled with passive, weak monsters means that heroes get imbalanced real soon, and normal units lag behind.

Another problem I see with the current levelling speed is my prestige going to massive amounts.

Sincerely
~ Kongde

Zero exaggeration. I keep 'notes of significance' when I play my games (see my game threads). My jaw dropped when I leveled after only the one kill. The fact that it was consistence with the next hero I hired was even more concerning.

I didn't think I had potential on either champ. Does Gilden start with potential?

My city leveling was the biggest shocker though. Had sovereign's call cast, so I was gaining 3 per turn. However, on turn 1 it said I needed only 20 more population. So....turn 7, it leveled. Not even enough time to scout around my city.

Try playing Altar with their experience bonuses, and Potential, and a henchman with Potential.  Even at level 20+ it goes pretty fast.

Altar city leveling is also basically as fast as you can get food because of their ability to get faction prestige from quests.  1 Prestige = 1 pop per turn.  Who needs Sovereign's Call when you have 20 prestige?  Of course (broken record) if population doesn't do much, then who cares how fast your city grows.

I honestly think they're boring, they don't do anything to make my champion more unique and fun.

Sincerely
~ Kongdej