I did various random configurations on my car. All stock to start, then added the TB traction bar up front. Nice turn in improvement and less torque steer. Added Koni Orange rears, TB torsion brace, and swapped from the factory Bridgestones to the factory
Michelin A/S3's. Ride quality was nicely improved, went from a 2/10 stock to about a 4/10, all while not really giving up too much in the handling department (unless you're completely flinging it around, then yes the all seasons show their true identity).
I was overall pretty happy but the car had some body roll that I wanted to get rid of, and I wanted to lower it a bit. Added the Whiteline springs and here is where things got interesting. Driving around in a straight line was a big improvement in ride quality. I would say 6.5/10 now, up front 4/10 with the stock springs. Around this time I started to spend a lot of time on the highway driving to see my lady friend, so corner hooning decreased while straight line cruising increased.
After everything had settled in, the drop on the springs was about as advertised however I do wish it wasn't quite as much, but it never rubbed in 98% of driving scenarios. A steep driveway would get the rubber underbody air dam, but what was most concerning was the rubbing and noticeable decrease in handling at the limit. Taking a tighter turn at speed would result in weird weight transfers and the outside tires (I think both F&R, definitely at least rear) would rub the fender liner or tabs. I never noticed any marks on the fender lip.
6-7 months went by and I kinda just lived with it. I didn't drive it in the same exciting way I used to, plus I have a fully prepped actual track day car so I just said meh to the handling downgrade and enjoyed the smoother highway driving. Then one day I started to notice the back end bouncing more than before when hitting bumps. Having used Koni on my Mustang before, they are horrible durability wise on that application and it appears the same thing happened here. They are already dead. I swapped the stock shocks back on and also removed the torsion bar because it was groaning a lot, and my goodness this car is back to handling the way a Fiesta ST should. The turn in is crisp, never rubs, and weight transfer/body roll is very controlled. Ride quality on the highway has gone downhill as expected, but it's still a little better than stock. Around town I notice no difference.
I'm not talking smack on any particular part here, as I know they all can work well in certain scenarios, but if you care about handling do not run Koni Oranges with Whiteline springs.