This isn't going to be a completely fair comparison as the sizes vary a bit, but hopefully it will be helpful. Last year I ran the RT-615's in 275/40/17. This year I am running the Advan Neova's in 285/30/18. All I can say is that these two tires feel COMPLETELY different.
First off, the Azenis worked best at around 38psi front, 42 psi rear. The Neova's work best at around 28-30psi front, 32 psi rear. They respond to pressure changes way different.
The Azenis had quicker, snappier turn-in, but this could be caused by different wheel offset, not really sure. The Neova is a bit slower on turn in, but seems to have much more overall grip through the corner. And the grip just feels different. I can't really even put it in words. The first time I drove the Neova's at an autocross I was almost speechless at how they felt. I will try to get on them again this weekend at a test and tune day before my next autocross so that I can figure out how to put it in words.
As far as wear on the Azenis - I got about 12 autocrosses, 60 drag launches, 20000 HARD miles with lots of negative camber, and then the inside edge just started to wear smooth. One other difference in wear, the surface of the Azenis was always very smooth as it wore(high silica content?), whereas the Neova's have a very rough texture. I only have about a thousand miles on the Neovas, so time will tell how well they wear, but I don't think they will last as long as the Azenis.
The only reason I switched to the Advan Neovas was because the Azenis weren't available in a 285/30/18. If they do come out with that size, it will be a tough decision when this set wears out!