Does the game send feedback to the ClubSport pedals? I was unaware there was force feedback to the pedals ...
Using a G27 and DFGT, braking is extremely unrealistic compared to a real car. In a car you use brake feel to judge how much pressure to apply; in GT5 you basically make a guess at how much brake pressure to apply. Other than damage, braking is the most unrealistic part of GT5.
GT5 doesn't send feedback but CSP have a load cell (pressure sensitivity, not travel sensitivity) which offers an unmatched realism on that matter, and CSP have a vibration motor which simulates lock-up feedback (you have to set it for each car if you want, I use it just as a measure for my pressure, I've set it up so that it vibrates when I reach 100%).
I had the "pleasure" of using a G25 once and man... that was the most unrealistic experience I've had. I even got worried since my wheel didn't arrive yet at the time, so I asked myself "did I waste 500 euros".
But man, CSPs are better than my real car's pedals.