Any racing wheel someone use will not determine if they are fast or not.. but my buddy who lives 10 min away from me has a G29 and when he comes over he always tells me it’s way easier for him to drive and feel the car on my wheel. Good wheels could help you get a better feel for any racing games physics.
Correct, it won't make you faster, but there are benefits that could make you better. I can see a big difference in my driving since moving from a Logitech G923 to a Fanatec DD Pro (8Nm). The biggest difference is how immediate the feedback comes through and how the large dynamic range of FFB allows the wheel to transmit the small signals that can get lost or buried in weaker wheels.
I have had it for a few weeks now, and in my WRC 10 league I went from targeting top 10s to being a regular podium finisher. Even got a win and a couple Power Stage victories, and there are a few aliens in this league. And in the final season of GTS, as a low DR A player seeded next to last in all three races I did, I punched way above my weight and ended up 63rd overall in USA despite staying way clear of the meta car. Race 1, didn't participate. Race 2 & 4 used the WRX. Race 3 was karts.
There is really nothing that has changed regarding my speed in WRC 10. The difference there comes from the confidence gained by receiving the information in a more immediate, informative and smooth manner. I find myself pushing and taking risks in places that previously I would have erred on the side of caution. In GTS it did allow me to consistently be a couple tenths faster but the biggest help, again, was the confidence I felt during the races which allowed me to improve my consistency as well as push closer to my limit in a more comfortable manner.
I used Logitech since 2008 and I still highly recommend it as a wheel. It is very solid equipment and most games have good support for it. Don't take this as an elitist post, rather I am just sharing my experience. Granted it's a more than 50% more money to start with the Fanatec vs the Logitech and that is a consideration that carries very heavy weight for many people considering the expenditure.
Unfortunately it seems that since GT went to Thrustmaster (and now Fanatec) that PD has totally ignored Logitech and GTS was by far the worst FFB I had on any game I have played in the past few years (WRCs, DiRT Rallies, AC, ACC, Project CARS...)
So I would say a wheel upgrade will not make you faster, but it can make you better.