I recently got my racing rig running again and considering my Logitech G27 is well past it's warranty I started making some mods to it to improve the feeling.
Upgraded springs in the pedals. Big improvement on the brake pedal, still not as good as a load-cell but its A LOT better. Clutch and Accelerator springs are about twice as heavy now. I prefer heavier pedals.
Replaced shifter spring with a solid piece of plastic. Ridiculously more resistance when shifting. It seriously went from like 500G to 4KG of force required to shift. Reminds me of my old Mustang now.
Magnetic ring for paddle shifters. I need to work on this because it doesn't feel as good as I would have liked still.
The Logitech G25/G27/G29/G920/G923 are still very much entry level wheels. Probably the best entry level wheels, but any Direct Drive wheel will feel substantially better.