I've only just bought the game this week too. I completed the training modes last night and unlocked Realistic and sim mode.
I haven't tried Sim mode yet but Realistic was soo much better than Arcade!!
You actually have to use some skill to follow a plane and shoot it down. Plus I found it far more realistic to land on realistic (Prob why they called it that!). I had to fight a little to steady the plane and it made it a lot more satisfying when I landed.
I've played for about three hours so far and I'm loving it! And I haven't even started the missions yet!!