I decided to give this a try. Went ahead and bought the game out of boredom.
With the correct settings (assists off (especially ABS off seems to be very important, otherwise braking feel is ruined), force feedback on minimum setting, low steering sensitivity (results in about 720 degree wheel rotation), etc.), this game/sim is really good!
The "supercars" aren't the best cars for showing off the physics, so the initial impression wasn't great. However, most of the other cars feel great with the G25. 348tb challenge, 355 berlinetta, 360 modena, 430 gt2, etc. They all feel really good to drive!
There's still some fps drops like in Ferrari Challenge, but it's minor. Overall the game runs a lot more smooth now. Graphics seem to have improved a little (more AA this time) and they aren't as dark anymore as they were in FC.
Steering input has been smoothened out aswell. The deadzone and steering lag from FC are 99% gone. I would say regarding steering input and linearity, this is easily the best racing game/sim available on the PS3. It's really good.
The physics have improved aswell IMO. Basically they feel pretty much the same as Ferrari Challenge, but more detailed. Especially when the tail of the car is stepping out, there's a lot more control now. FC sometimes felt a little arcade-ish when sliding around the cars... like the game would help you with countersteering (it was a little too easy sometimes). This is gone now.
Weight feeling of the cars is still as good as in FC. Aswell as the rest of the game, it simply feels a little more smooth and detailed in SC now.
The only real issue i had with the game was the following:
When i first played it, i set ABS to 1 (ABS is on, but on minimal setting). This results in cars that don't let you feel when they start understeering, which feels absolutely terrible. FC never felt like that, so in the beginning, i almost gave up on the game (to my luck i tried a little longer). With ABS off (and minimum FF strenght), you can feel when the front tires lock up, or when you turn to hard and you start to develop understeer.
Another thing which only added to the issue was the force feedback. I had set FF to maximum strenght, which also seems to be a bad idea in SC.
I generally like strong force feedback, but what happens in SC when you use maximum strenght, is that the effects get "washed out", and you don't feel the "soft" effects anymore, which results in a numb feeling car. In order to get the best FF in Supercar Challenge, you need to use the lowest FF setting. This way, the strong effects stay strong, and the soft ones are, well... soft, and you can still feel everything.
It seems that with the wrong settings, SC feels quite bad, but with the right settings, it's a dream. Again, steering input/response and force feedback are brilliant (for a PS3 game)!
Overall i'm really impressed with Supercar Challenge (so much that i've played it for the whole weekend).
One thing they deserve a medal for is the new additional in-car view (closer to the windshield, steering wheel barely visible). In some of the cars it almost feels like iracing when the steering wheel is disabled in the car. It is the perfect view for driving with a G25.
I love it!
PS: Clutch still isn't working. The funny part is, in FC, in the game menu, they displayed a G25 including the shifter and pedals, labeling the controls. The clutch was labeled as "clutch", but was never working. The fix for this in Supercar Challenge... is... *drumroll*... the clutch isn't labeled anymore in the picture! LOL!
PS2: For physics comparison... it's A LOT better than GT5P IMO.
EDIT: With a gamepad it's fun aswell, but you'll miss out on the great force feedback and driving experience with the G25. Plus it feels like there's still lots of steering help with the pad. Nevertheless, it's still fun to play without a wheel.