Yes they make a difference, as the even when brand new, the plastic bushings deform some under force, and also develop quite a substantial amount of slop with higher miles. I believe the solid gt3-style bushings do not only not deflect as much under force when new, but would also not develop such wear with higher miles on them.
If you are a DIY type, you can make your own gt3 style shift console from a plain-Jane 997 style console with the plastic bushes by installing the Phenix engineering bushing kit (cost $65):
https://phenixengineering.com/shop/porsche-997-gt3-style-billet-shift-bushing-kit/
I've got the phenix engineering bushings and am just about done completing an installation in a low miles standard 997-style shift console. Might post some pics and more substantial review later. Coming off the car is a very worn out 986 style shift console. With about 110k miles, the plastic bushings were quite sloppy and this resulted in noticeable side-to-side play in the shift knob.