Asseto Corsa will be fantastic.... in one to two years. It is still in very early beta stages. Rf2 is finally looking and playing much better and it took time to get there. AC will be the same in that respect.
After playing AC for a few hours there are good and bad things of course. One being the AA... ARGGG its got AA problems just like rF2 but worse! The physics of the cars look amazing, but the FFB doesn't do them justice, so its like the reverse of rF2 where the FFB and physics feel amazing, but don't show it in replays. The HDRI has issues also in AC where is gets over blown or isn't set right as it is now. Rf2 has better replay cameras. AC replay cameras are either too low, or too close so you can't really see what the car is doing, and there isn't any fancy track or turn specific cams like rF2 has. All that aside I think it is good and will be great in time. Right now it is not an rF2 killer by any means. I am just glad I have another promising sim to play.