I agree with everything said here, but for me personally I find the RWD cars in LFS too difficult to control.
In LFS I'm well able to race in all FWD and 4WD cars, but seem unable to race correctly in the RWD cars. They seem too slippery to me and I cannot consequently race them without losing them at some corner, even the low powered cars or maybe especially even the low powered cars. For some reason in GT5p I've just got a way better feel with the RWD cars and this has to do with the feedback the game gives in my opinion, not necessarily difficulty, but I don't know what exactly is different. What FWD and 4WD feels like to me in LFS is similar to what RWD feels like to me in GT5p; predictable, understandable and correctable.
The RWD feel in GT5P seems to me more real, because I cannot imagine an RWD to actually drive that difficult in real life or I would expect a lot more crashes irl.
I expect the new tyre physics to change this feel (for better or worse )and maybe Scawen is able to explain how his expected changes might influence the handling or what effects were seen that caused him to start rethinking the physics in the first place..