As promised in my last thread, here is my review of my recently purchased Advan Neova AD08R in 215/40 on the stock rims. I postponed my review until I had taken the car down one of my favorite roads with many low speed turns at the end of drastic changes in elevation that can really test a driver's equipment and skill.
After driving on them daily for the past month and 1000 miles I can actually recommend them as a replacement for the stock Potenzas.
Ride quality is pretty close to the stockers so far though I've heard they develop more road noise after they wear in. They are communicative of road conditions though not entirely harsh.
Grip is insane. Much better than stock. Both in straight line and lateral. Full launch control yields no wheelspin or chirp with 1st to 2nd shifts though I'm only stage 1 at the moment so I'll notice more as I increase power later on. In slow turns higher speeds are definitely doable though I don't notice as much oversteer as before, and no understeer, it just hooks and goes.
Communication is greatly improved. In hard acceleration from a turn you can feel the driver aids kicking in that the stockers didn't communicate. You can feel everything on the road all the way down to the painted stripes on the side of the road.
Can't speak on gas mileage one way or another.
Now for the bad things. They are heavy. But that extra side wall strength has to come from somewhere. Acceleration is a bit slower as a result, but the increased grip offsets it.
They aren't cheap either. At $175 ish per tire they are about $25/tire higher than the stockers and other top picks like Dunlop Direzzas. But so far they seem worth it.