I feel like the wheel will make you faster in the high downforce cars, but it doesn't matter as much for most road cars and groups like GR4, GRB and maybe GR3.
Agree the skyline was tricky. I tried the wheel at Spa with the Supra GR3 car, something i am really familiar with and good with, I got within 1.5 seconds of my best time, the downforce and grip make it easier to gell with. THe road cars feel absolutely horrible.That Skyline is not exactly the smoothest car in the game and the handling is a bit poor but it's far from undriveable and you can drive it smootly. Maybe your wheel doesnt work well
wheel all the way is better. faster for me as i can be smoother and it the turns correctly. can feel the road surface way better.