The view restriction is a difficult one.
To mimic real-life you need a good field-of-view and a good sound setup so you can hear where the other car is. A lot of people can't do that.
I've had a little go in a single-seater as Tristan knows
You are definitely aware of cars by your side in your peripheral vision and through the sound they make, more so than in patch X30 with a single monitor.
That said, I'm still joining