I owned an ERay for 6 months and now own a C8 Z06. I had a C8 Stingray also for 4 years and tracked it. I bought the Eray convinced the AWD would be better for me especially on the track. I am a good driver but not the fastest by any means. FYI for comparison I used the same tires on all my C8 the MPSS4s. The Stingray was a good car but the brakes were the biggest problem. The brakes did not hold up on track even after changing rotors 3 times and 4 different pad compounds. I moved on the the ERay as it was described as a very capable track car and I knew the Z06 was may more car than I could use, based on my ability. The ERay lives up to its reputation fast acceleration, pulls through the corners and is better in variable weather conditions. It was fantastic on the track for 2 or 3 laps, likely faster than a Z06 to that point except on long straightaways. Then after 2 laps or so the battery recharge could not keep up. GM put a feature in the Eray "charge +" to compensate discharge to charge the battery faster, but at a cost. As soon as you hit the charge + button (inconveniently placed at your thigh so you have to take your hand off the wheel and find it somewhere on the side of the console), the front drive motor turns into a generator. This causes 2 major changes; the steering feeling changes suddenly and gets heavier, and the engine horsepower is burdened by the front drive - now a generator - actually reducing power to accelerate. This cut lap times down significantly due to the reduced HP taken by the front drive motor. I would say at that point the car is slower than a Stingray. I loved driving the Eray but this was car bipolar and I would have to live with that and learn to drive on track with that handicap which took away from the enjoyment for me. On the street the Eray never used up battery power and was "ON" when you wanted it to be for short bursts and it had a neat party trick "Stealth Mode". Most people including "Corvette enthusiasts" do not understand the car and like to criticize it. I found it frustrating explaining to people especially Z06 owners who do not track their cars that the ERay is the best option for the majority of Corvette owners. Some of these Z06 owners opt for the Z07 package and then replace the Cup 2's with the Eray All Season tires for a better driving feel etc.
I got the Z06 a few weeks back and just broke it in 2400kms for the track. I did one good track day a few days ago and this is the right car for me even though I will never be able to drive it at its limit. I hope to get in a few more track days before the season ends and may have more to say. Today I say buy the Eray if you are looking for an upgrade from the Stingray, unless you are going to do more than 2 or 3 track days a year. The ERay will eventually win over more Corvette enthusiasts over the next few years IMO.