I've had my wheel and pedals for a couple weeks now, and they're awesome. I knew there would be a learning curve, but I knew it would be worth it.
When I ordered them, I spent the next few nights setting my fastest times on several tracks with my DS4 to give me something to compare to. I like to go to Circuit Experience when setting track times. I set new best sector times and track times, and went as fast as I could go, thinking it could end up taking a long time to beat them with my wheel.
My wheel got here and I installed firmware and drivers, calibrated, and played with all the settings (It's a fanatec setup), and finally started trying to drive fast. I went to Brands Hatch first and just worked on the first sector, since that first turn is a tough one to get right. I ended up beating my time after about 20-30 attempts, all while not being used to my new rig at all. I beat the first 3 sectors that night, while changing and trying to figure out the settings. I beat the whole track the next night, along with Willow Springs.
I was getting used to it and my foot was getting calibrated to the brake force settings and stuff. Over the next several days I beat my other times, sometimes by 1.5seconds or more, and I could certainly beat them by more since I would just beat the time and move on to the next track without further laps. The last track to fall was Interlagos, as that's my best track. My Circuit Experience time was 134.6xx with the DS4, and I beat it by .2 secs. That one felt good, since I was so consistent with my controller (on that track, at least). I think the difference is the ability to be more consistent overall.
I can put the car where I want to now. I can feel how the weight is shifting and adjust mid-corner using left and right foot at the same time. I can modulate the brake and throttle with much more precision, compared to the DS4 right analog stick, which I was using for gas/brake. Trailbraking is much better now, since I have more precision, but also I can start loading up the drivetrain with a little throttle at the same time - making the transition to accelerating out of the turn much smoother and faster. I also realized I had been understeering massively with the DS4 on several turns on different tracks, since I'd often just whip the steering all the way over going in to certain turns.. and now I rarely ever use even half of my steering angle.
The driving aids I use are ABS default and TCS 2. I try to not activate the TCS at all, and I think that's a key point. If you accelerate smoothly and time the throttle increase with your ever reducing steering angle out of a turn, the TCS won't kick on and "stall" your progress. This has become much easier with a driving rig. TCS 1 is hard for me still, but at least now I can get around a track without spinning usually. The problem is that I'm too conservative with the throttle when TCS is 1 or 0, so my goal is to get better there.
You'll get faster once you start thinking about the strengths of your setup compared to DS4 and trying to maximize those on every single turn.
I wouldn't try doing that just yet my good sir. 
