The Iconians are one of the iconic races of the Galactic Civilizations series. They're known for receiving a huge boost to science at the expense of huge penalties elsewhere. The question when playing the Iconians is always: "Is it worth it?"
I played a (very short) game with the Iconians recently, and it led me to the conclusion that the Iconians presently are much too weak.
Currently the Iconians get +150% research (for some reason the civilization selection screen says they only get 50%) at the cost of a major reduction in influence and -3 diplomacy.
It's not yet clear to me how much of a factor influence is going to play in GC4, so I can't say yet whether the Iconian influence penalty is problematic. Instead, I am going to focus on two aspects of the Iconians: their ideology and diplomacy.
The Iconians have their "default ideology" set to Secrecy. I find this to problematic because Secrecy is without a doubt the worst Ideology you can take. You can look for my forthcoming review of Secrecy in this thread. Having the extra awareness in Secrecy is just a waste and it means that early on, the Iconians don't have any good traits available to them. This is problematic because the early game can get very, very rough for the Iconians. (Another problem is that Darkness--which would probably be the trait next to Hidden Agenda that the Iconians would want the most--has absolutely horrible synergy because the Iconians have the worst influence in the game.)
In my game with the Iconians, I was playing on Incredible difficulty. (I like to challenge myself and I don't think that I should necessarily win every game.) Other civilizations were to set to be "Distant" and I was playing with large sectors, but none the less next door to me were the Festrons. (They weren't terribly close, but I definitely would not call them "Distant.") Because I started with a -3 penalty to diplomacy, the Festron declared war on me about two turns after meeting me. Actually, it was as soon as I discovered the Universal Translator technology. I think you can all deduce how the rest of my game went. It was over in less than an hour.
Now, I'm a big fan of the concept of the Iconians. I liked the sensation of playing the Iconians in GC3 and feeling like you were taking a huge gamble. In GC4, it just feels like Russian roulette. If you get lucky, you might be okay; otherwise, your game is just over. Part of why I liked GC3 so much* is that it didn't often feel like it put me in those types of situations. The big problem with games in the Civilization series is there's always a chance you end up with bad terrain next to Attila the Hun and there's just no point in playing the game because you already know how it's going to end. With my Iconians game, I got a little flash of PTSD from my days playing Civ 4, 5, and 6.
Obviously, this wouldn't happen in every game. Still, I feel like it would happen too often. The one good thing about being in the Secrecy tree is you can take Hidden Agenda to keep yourself alive a little longer. Unfortunately, you're probably going to be dead before you get all the way down the secrecy tree.
Perhaps fixing the Iconians could be as simple as reducing the diplomacy penalty from -3 to -2.
(As a side note, I want to mention that it seems a bit ridiculous that in the previous game, the Iconians were Craven, whereas in this game they are Courageous. This may be a relatively minor point, but one I want to make anyway. Consistency in lore and such matters to the fan base.)
* CG3 is (at least in concept if not always execution) the best strategy game I've ever played; and this is coming from someone who plays a lot of strategy games.