My first impressions
I had been holding off on preordering because I wasn't really sure whether the concept would work -- 4X and real-time don't intuitively seem to go hand-in-hand. I've been pleasantly surprised, and although things are still rough around the edges from being in beta state I'm pretty convinced the core concept can work.
Here are a few things I noted as a brand-new player, familiar with other 4X games and RTS games but not having followed Sins much in the past and mostly coming in blind:
1. Inside the game on the top of the screen is a little toggle button that controls whether zooming auto-pans to keep the mouse on the same point in world-space both before and after the zoom. This feature is indispensable to me and once I toggled it on the UI instantly became ten times more comfortable to me. The problem is that I had gone for my whole first game and much of the second before I even realized it was there. I had looked under options->controls for a toggle to turn on the same feature and hadn't bothered to read the hovertext on all those little icons above until later.
It would help a TON to add a toggle somewhere in options->controls, even if all the toggle does is the same thing as that little button in game. Under options is the first place most people would look for such a switch.
I'd consider also having it turned on by default, but I'm not sure how other people feel about it. My gut feeling is that toggled in is the intuitive way to zoom in or out, but that might just be because I've played Supreme Commander a lot and that's how it handles zoom by default.
2. The chat scrollback window can be scrolled up and down with the mouse wheel even when invisible, which doesn't work well if I want to zoom in on something in the top third of the screen. If this could be changed to something like not taking mouse focus while hidden or only taking mouse focus while explicitly turned on (via enter or whatever the start-chat key is) it would make zoom a lot more intuitive, especially when the zoom mode mentioned in (1) is turned on.
3. Right now when you place a structure it instantly pops up at 0hp and then starts going up once a constructor ship gets there to start work. This means if you want to start building defenses in a place that keeps getting attacked, you can only queue up a few or else most will get killed before construction can even begin. The idea of them starting off easily-destroyed until a construction unit finishes is fine, but the current implementation increases micromanagement.
If it were changed to something along the lines of "clicking build queues up a build but doesn't actually place the 0hp structure until the construction unit gets there" it would allow you to queue up 15 turrets all at once and turn your attention elsewhere without having to worry that any attack will instantly kill the 12 or so that haven't started construction yet.
As it is you can get it to work the way I describe if you micromanage it so that you only queue up a new building when you have a free construction ship, but in the example above this would mean you have to baby-sit the constructors, constantly adding new build orders each time an old one finishes.
4. Culture lines don't seem to display correctly when very small. It seems that the lines start off in the middle of the gravity well and don't display until they get past it unless you zoom out and quickly look at them before the icon view finishes fading out. If you could change it graphically (keeping the gameplay elements the same, just a visual change) so that when zoomed in the lines start at the well (meaning a .1% culture line would be just a pixel or two at the end of the gravity well) it would make it easier for first-timers like me to understand that yes, your broadcaster is working and culture is spreading, it's just not very far yet.
5. It'd be nice if colony ships set to auto wouldn't colonize a planet if it would instantly flip and trying to manually colonize using one would give a warning first about insta-flip before following through. Sometimes it's not obvious when it would insta-flip (for instance I've had it insta-flip when it had culture going about 10% out through all 3 lines and my own culture was 90% to the planet through two of the three lines) and it'd be nice to not accidentally give away planets (or worse, have an AI ally repeatedly give away a planet you keep bombing).
6. Unit AI still needs a lot of work. Very often I'll have a couple dozen bomber squads decide that instead of blowing up juicy targets they should all spend five minutes trying to kill a lone fighter squadron. I assume this is mostly from being in a beta state, but still worth mentioning. I'd hope that ideally I could send a fleet to a planet and expect it would do 90% as well by itself as if I were actively controlling it, unless I have some special objectives like wanting to take out their broadcast towers at all costs.
7. Bombers seem really powerful, almost to the point that it's always useful for a fleet to be 75% light carriers. They seem to be completely immune to gauss turrets and almost everything else aside from fighters and flak frigates, and compared to everything except fighters they are FAST. I hesitate to mention this since I'm still very new to the game and don't have a great handle on balance yet, but if there were some sort of static base anti-air (a new kind of turret, an extra research unlock to let gauss guns target them, adding anti-air guns to hangars, etc) it'd make mixed forces a lot more attractive.
8. Units have trouble intercepting. If I send a bomber after a fast-moving scout frigate, it won't try to "lead" the target at all and never manages to catch up even though the bomber easily could have if it steered a little farther to one side. This is probably a unit AI subject, but basically if you're trying to intercept a fast-moving ship you want to steer towards where it will be when you get to it rather than where it is right now.
These are the main things that stood out to me in a couple days of playing. Along with all of this criticism, some positive commentary - even with all of these issues and with being far from complete, the game is fun to play already. I'm feeling good about the game and think that by release things will be getting pretty awesome.
