All the things that are really important to me:
-Added name of tyres on the car within the pre-race menu. (hopefully it doesn't just say Automatic by Weather for cars with that setting)
-Resolved changes of Helmet Camera settings not saving properly via the Pause Menu Options. (finally!)
-Added a central cockpit camera to cars and the options screen. (your PC1 "GoPro" camera is back)
-Ferrari 333SP: small balance of performance changes to fit with other LMP900 cars. Fixed final drive ratios and improved AI gear usage. (It can now reach top speed and use top gear)
-Formula C and Formula R: revised tyres, engine braking, and damper setup for better stability and easier driveability. Revised Stable setups. Adjusted FFB for changes to tyres. Fixed rain tyre being faster than the slick.
-Formula Cars: decreased sensitivity to aero and suspension damage.
-LMP2 cars: gave approx’ 50hp power increase to get them closer to real-world lap times, and adjusted radiator sizes to suit. (Should be a bit more than 50 but it's something. Real life they're ~600HP now)
-GT3 Soft Slicks: tweaks to temperature operating window to broaden their range, mainly fixing their poor performance in cold conditions. (I think we all noticed this one)
-Driver helmet now correctly shown in Helmet View camera. (Didn't know what was wrong but I'm curious to see how it changed)
-Improvements to the cut-track penalty system now takes into account crashed, pitted, and other class opponents in timed races.
-Fixed an issue where a player would incorrectly receive a time penalty when hit by another player during the formation lap. (no more stupid frustration there)
-Pretty much everything under the AI section.