Okay, so I wanted to answer the Poll questions, for myself ...

(1) The two games I have thus far completed, playing v0.915, have been on the Easy level.  Prior to v0.915, I played 2/3 of my games (six total) on the Beginner level, and 1/3 on the Easy level. 

(2) The reason I choose to play on these easier levels, is principally because I want to have a good prospect of winning the game.  I think that makes me a more "casual" player, than a majority of the folks who are currently in the Beta-testing group.  I  am  willing to lose occasionally; but I don't want to "waste" a lot of game time, playing what are essentially "losing games" for me, or otherwise feel like I am playing at a "miserable" level.  Also, I want to enjoy the "first X" (eXploration) as much as possible, and I find that is more likely to occur (at least in the early game) if I play on a relatively easy level. 

(3) For the future, I am trying to decide whether I will play my next game at the Normal level.  Whether or not I do, I expect eventually that I will be playing most of my games on the Normal level.  Thereafter, I may occasionally play at the next higher level too (Challenging level); but (at least at this point) I doubt if I will ever (or often) try to play at a more difficult level.  Again, I wouldn't really expect that to be much *FUN* for me personally. 

Of course, this is all subject to change, depending on how the Developers evolve the game further ...     

1) I'm mostly playing on Challenging at the moment, after starting out with a few games on Easy and Normal.

2) I think this is the level at which the AI uses its full power but doesn't cheat*, so that suits my desire for a decent opponent but also a fun game I can roleplay in or spend time exploring and getting to know my rivals.

3) Judging by my experiences with GalCiv II, where I topped out at Painful, I expect that I won't go much above Hard. I'm not particularly interested in hardcore games - I want to be able to mess around and make mistakes.

*except for monster guardians, early escape from Tremor, extra paths for sovereigns, unlimited pioneers, stacking burning blade, early access to Tireless March, being pass off a "demand tribute" as an "offer tribute" and a seemingly bottomless mana pool. But then again, these balance the rush-refund cheat, circumventing the diplomatic wait period, easy surrenders, and reloading, all of which I resort to on occasion (don't judge me).

I play Hard most of the time. I like the AI having a little bonus because it's never going to be human-like in intelligence. I'm also a big fan of larger battles and those seem to happen more the higher the difficulty.

I only play on Normal difficulty until next beta. I want to experience the entire game each time I play. When more balance is applied to the game and bugs are ironed out I will increase the difficulty.

I played a game of "insane" last night.  I like the drop down when you hover over it.  It says something like "you have issues".

After playing for 2 hours my brain was spent.  I could not for the life of me figure out how to get out of my crappy situation.  I was beating monsters back left and right, and a couple times I had to let my man take a chance at getting a full beat-down just so that I could try and get to a piece of treasure.  After a while I even took my only partners soul out of desperation.  He was beat to shitz by then anyway.

It was fun, short and sweet.  Still had my trusty rusty sword when I fell.

If anyone is listening out there.  I would LOVE that when you play on harder difficulties, somehow the real power numbers of other players are scaled as to hide the true power. 

i.e.  Let them have the money, mana, and whatever, but dont let me know how powerful they really are.

It takes a little bite out your sails when your 13 and your neighbor is 512 after 50 or so turns.

Trying to get a treaty out of someone who has 141230 gold compared to your paltry 220 is kinda hard also.

Maybe you could just move the decimal up one for each difficulty?  Just a thought.

I've been playing on expert because I found challenging easy. But expert has proven too hard! I've been close to winning twice, but both savegames got bugged, so I had to give up.  Not sure if Im being a sore looser, but it does seem that the difficulty curve between challenging and expert is quite steep! I think I'll go back to challenging until my skills improve. I expect I'll eventually be able to master expert, but Im not sure If I'll be able to advance beyond that.

I have been playing on challenging since 0.914.   I enjoy the feel of the game at this level although sometimes, as others have commented as well, I find the end game a bit too easy.  However the beginning of the game can actually be a challenge depending on where you are initially placed.   I have lost or abandoned a few games where I was hemmed in by monster groups that were too powerful for me to expand which left me at a disadvantage when I eventually engaged the other factions.   I expect to try moving up a level soon to see if I can get into a match where the end game is more exciting.

I play on Normal because I am focusing largely on how the game plays with its standard "balance". I'll play the game for my own enjoyment when it is done.

Once it is all in line on normal, then the other levels can be scaled appropriately, but you can't really balance the game on high difficulties and expect it to trickle down properly.

I am playing among Novice, Beginner, and Easy.  Easy still kicks my ass in terms of NPC AI (other factions).

I've only played normal so far as I just started. I really dislike playing vs a cheating AI since it becomes more of a grind than a strategic victory. I will probably bump up to Challenging but not go any higher. I am probably good enough at strategy games to win on the hardest difficulty but its less fun for me.

before .915 I was playing on challenging and wiping the floor easily, with any team I picked.  So I bumped it to hard which is what I played most of the games at in .915.  I haven't lost one of those games yet.  Didn't abuse any cheese strategies to win either (def no quickloading), was just better at questing/loot finding, and making a pointier stick than the ai.

I've started a game as Ythril on expert now, and have just wiped out the first team.  Almost taken out the next.  I'm hoping to get a diplo victory.  but if I can't, the last team should be too hard to take out from my position now.  Expert has neutered my ability to get good equip though.  Nowhere near as quick as the AI in getting good equip.  I've actually had to  build an army  to help my champions (this is a good thing).

I have noticed a similar thing though with how the game plays once you are at war with someone.  If you win the first battles against their champs, you should win the war.  Once you get the drop on even expert players, you can push and take a city, recoup breifly, push and take the next.  I am burning my mana more than I was on Hard (no stockpiles of 500+) which is good.  Mean's I am really having to work for each small victory.

Challenging