OK, I've played through the first 3 races in the builders cup intro, enjoying it so far, I think anyone that enjoyed previous Forza Motorsport games will be at home.
I'm playing on a pad, in cockpit view (FOV 65), Sim steering (tried normal, preferred sim) all assists off except for ABS (tried ABS off locking too much, might lower max deadzone). Race difficulty at Expert (Damage, fuel, tyre wear, race regs) with AI set on 7/8.
With those settings and starting around 9th or 10th my best race finish was a 3rd place, I finished the 3 race championship join 1st. My starter car (Scooby) is around level 18 now. I should do better now ive started playing with the tuning / parts I have available and have the game settings how I like them.
The only annoying thing I've found so far is being able to hear my own engine, I've set all audio except my car to 50% but it's still pretty quiet even with a race exhaust. It might just be the Scooby or cockpit view.
With the premium upgrade, I've started with 20 cars and 500k.
I think tomorrow I'll race some spec multiplayer to try to get a decent DR/SR before the masses start playing, so I'll hopefully be out of the banger racing group going forward.