Of all aircraft I've tested since the patch, the P-38s took the biggest hit resulting from"Made several changes to the flight model affecting static thrust, propeller slipstream effects, ground effect, flaps and slats."
You should have noticed that the sink rate in the ground effect has increased for all aircraft.
Some aircraft saw a positive change. For example, the F6F-5 is no longer floppy with full flaps. You can turn continuous circles as slow as 101 mph. That's a marked improvement as the previous F6F-5 would depart at 112-115 mph. Also not adversely affected were the F4Us. With full flaps, I can turn continuous circles at 99 mph in an F4U-1D. Both of these can be flown into the buffet without serious consequence, although the F6F seems more at ease nose high. You can get the P-47D-11 down to 106 mph doing the same thing, and its quite stable.
P-51s show no major changes, but can only manage about 121 mph in a full flap, minimum speed circle. It will not sustain getting it slower. P-38s are now only slightly better than the P-51s in this respect.
109s lost their floppiness and handle beautifully now. Even the 190s show greater stability at low speeds, but getting them slow enough to utilize flaps requires a climbing turn or pulling off power.
Spitfires don't seem to have suffered, but their sink rates have increased enough to catch you by surprise.
Deadstick landings will require greater speed over the numbers (end of the runway) or you will drop like a stone when you attempt to flare.
What's important to remember is that if you are buffeting, you've already crossed the line and your turn performance is degrading.
My regards,
Widewing