First of all I have not played it but I have played Lock On Modern Air Combat.
Have you played Lock On before? This appears to be an evolution of that game. There is a free demo of Lock On available from lots of websites. I can't remember which one I got the demo from, just google "LOMAC demo".
Here is a download of the demo from CNET.
You can fly the A-10 in a single mission on the demo. You can also fly the Mig-29 in a dogfight against a Mirage. I don't think that the flight characteristics would change much between this demo and DCS A-10C. The graphics and game content are probably the main difference. Lock On was an awesome simulator to begin with.
Keep in mind this is a 2003 demo so the graphics are pretty crappy compared to modern games. It should give you an idea of how the game feels though. It's a completely realistic flight sim. If you put all the realism options on be prepared for a fun/frustrating time. If you try to turn too hard with a full load of munitions and get the angle of attack too high YOU WILL STALL AND SPIN with realism turned up. A single bullet can puncture your fuel tank and give you 1 minute before you run out of fuel.
As mentioned above if you like true simulators the DCS games are for you. If you want a game like "Ace Combat" stay away.
EDIT: One thing I like to do in the demo is put the landing gear down and do a touch and go on the road by the enemy tanks and APCs. For some reason when you touch down they recognize you as a target and the tanks and APCs will shoot at you if you come near again. The light tank has a SAM missile it can shoot at you and will shoot its rapid firing light cannon at you in the air.
Otherwise the only defenses you have to deal with is the single Shilka anti air vehicle with its quad cannons. It will blow you out of the air if you get too close but otherwise isn't too hard to deal with.
If you park on that road the full size tank will blow you up with its big cannon.
I also like to open my canopy in the A-10. If you are flying the canopy will rip off when you open it and all the sounds get louder. You can hear the cannon a lot better if you do that. Edited by Epitope - 5/31/11 at 6:07pm