I have a few different baseplates for my car, and found huge differences in feel from stiff to flexible. Strange thing is I honestly didn't think the flexible plate gave the car more traction. I know this is completely against what the experts say.
I did find the way they made their grip was very different. For example I found a soft plate gave a lot of initial response followed by midcorner push in fast sweepers, and on exit a lot of initial steering on first application of throttle followed by push a few feet out the corner. Also it seemed to stick more in slow turns.
A super stiff car seemed be quite unresponsive initally, often pushing all the way through sweepers. But very consistent if a little pushy on exit.
After some time experimenting I found a certain amount of flex was really good to help initiate the turn but was also stiff enough to preserve the midcorner steering in sweepers, and was sufficiently consistent on exit (and overall) so you could set your line and the car would stick to it onto the straight for example.
I ended up with a pretty stiff car. Much stiffer than the current crop of TC's.
Just to make things even more complicated I also found that if the car was set soft it worked a lot better with lower roll centres..(it never ends!)
Probably there will be someone who experienced the exact opposite of everything I did but if you can find a setup that works for you whatever the flex then that's got to be the best way to go regardless of the trend of the day.