I wish it was fun and arcadey, for me it is frustrating and daft.
Maybe it was the change in datasets for the physics that caught them off-guard with base setups.
I guess I should stress I am driving with zero aides, etc. I have driven at Spa in a crap Opel (sorry but it was a beater), and taken Eau Rouge around 60mph and did not slide off the track slapping into a flat spin.
I mainly kart race now (twice a month), and have done road racing and autocross. I am not an expert, but I love racing and normally love Forza more than any other console racer. I reserve the right to change my opinion based on more time with the game, and I am going to turn on driving aides to see what that adds back in.
I didn't see many changes in the simulation side. Try driving the RUF CTR Yellowbird -what a monster of a car, btw-
without assists in Bathurst (you can find it in the VIP Rivals challenges).
Or the 1965 Shelby Cobra 427 S/C for that matter. This is almost uncontrollable, too tail happy for my taste.
You can also drive the Bugatti Veyron Super Sport (2011) in Spa, and you can see that they are trying to recreate some interesting things with their physics.
Ford F150 SVT Raptor is also a nice challenge whenever you can try it.
Where this game shines the most compared to the previous games, apart from the new cockpit view is in the sound department.
Driving the Mazda #55 787B was one of the best resounding experiences I've ever had in a game.
All in all, I'd score Forza 5 with a 7.5. It would be a 9 but the aggressive behaviour of some Drivatars can make it impossible for people to complete a clean race. You don't need to have a fully clean race, but if I could only have a single clean lap....
Forza -common in the series, not only 5- goes too far punishing you when you cut a corner or go outside the track.
Crashing on others is also something they must keep on punishing, but the problem is that it's others who crash on me from behind, yet I can't complete a clean lap 'cos of that.
Punishing I am okay with as long as this happens in the lap you are in, but the punishments are carried over to the next lap for some reason I don't understand. This makes it very difficult to have a clean race or lap.
I like how they categorise the different kinds of laps though, and I agree that for example, a clean lap timed at 2:25:00 is better than a 2:23:00 lap if you cheated, crashed on others or couldn't keep the car in the track.
What is most frustrating for me is that a non clean lap can be carried over to the next and the originator of that can be a Drivatar that crashed on you just because it thought you needed a good hiding.