I use exclusively a mouse in LFS, and it is not a money issue.
If I had a choice I would race with a wheel , and I thank the devs for being able to drive with a mouse - without it I would never have bought a license.
Here are the positive and negative sides from my point of view:
Positive
Easier correction (faster virtual wheel movement)
Less strength required for steering
Easy setup
Space saver and portable solution (I only have a laptop and no desk, but on the other hand I can carry my LFS rig in a backpack
)
mouse accuracy - no mechanical friction or backlash added to lag
Silence - priceless, I could not use LFS with a wheel in the evenings as it would wake up my kids, flat too small
A mouse does not look like a toy - I see no way I could convince the miss that a wheel can be used by adults. And my kids are girls and too young to be of help there...
Driving with a mouse reduces addiction (because it is no so enjoyable). Don't know if it is positive though
Negative
No FFB; on/off pedals unless you use 2 axis (I get lost traing this) or strange gimmicks
Stress on hands / joints dificult to cope with in long races (above 10-20 min)
Less accuracy for small adjustments - combined with above it becomes difficult not to oversteer.
Absolutely unnatural way to steer a car (for RL drivers at least) - requires a high abstraction capacity to get enough immersion to enjoy a race.
Learning time and progress are worse I think because of the alien control - even less ways to feel what the car is up to, so you en up correcting instead of preventing unless you spend gazillion hours practicing to extract the maximum information from vision and sound only.
If I did not have to choose between my wife and a wheel, and if I had room for it, I would be driving with a wheel for sure. For the moment I try to make the best with mouse + laptop and I can assure you I can have fun & close races as well, despite some frustration.
You can check my times on LFSW, not fast but neither ridiculously slow. Powerful RWD are quite a challenge though.