For me: -Tire slip in some cases, when cornering and in some surfaces it's there but many times too subtle when braking lock it's not, and it's very important mostly when not using ABS. -Vertical suspension feedback, in jumps it's ok. -Track FFB or car related FFB, feels too smooth in some surfaces, it feels much better when the track has "bad track surface degradation", it's more alive. Spain Tarmac feels flat very very flat for example, but sand too.
From a old simracer: -Tire slip is there but not in all cases, must be more noticieable in for example wheel lock. - Road surface is too flat in some stages. I think it's a stage FFB resurface job, in surfaces that feel too flat like sand and tarmac. A lot of bugs aside FFB.