I have been running for so many years in many other brands. This new Kayano 18 is my first pair of ASICS. For me, the most noticeable difference is shock absorbing. I think we can immediately tell the difference in shock absorbing quality of different car models. This is a direct analogy. In this Kayano 18, I have the same feeling as riding in a Mercedes or a Lexus. The Kayano absorbs all the shocks. Each running step is firm and responsive; but no shocks. I used to run in the Adidas Supernova Glide 1 & 2 before the Kayano 18. The Supernovas are very good shoes which helped recover my injured knees caused by other previous wrong shoes but I prefer the Kayano 18. The Kayano provide perfect shock absorbing and are lighter. All in all, this is the most comfortable pair of running shoes I have ever owned.

I would like to add that the Supernova Glide and the Kayano are technically very different shoes. The Supernova Glide is in the "cushion" category for runners who are underpronators but the Kayano is in the "stability" category for overpronators. I am a neutral runner and have no problems running in any of them. The Kayano simply absorb more shocks and are lighter.

Update: I have recently purchased a pair of ASICS Nimbus 13. I use the Nimbus for recovery run. The difference between them is very obvious. The Kayano 18 gives more support at the midsole. This is because of the Duomax material (the gray part of the midsole under the arch) which is more stiff than the white softer midsole material. I feel more comfortable in the Kayano 18 especially when walking. I like the midsole support. I also run faster in the Kayano. The Nimbus, which is mainly for underpronators, does not have the Duomax support since the more stiff midsole may promote even more underpronation. The midsole of the Nimbus is uniform. When walking in the Nimbus, the feeling is like walking on a mattress. I found it too soft for long walk. I prefer walking in the Kayano which is more firm. When running in the Nimbus, the shoes give soft, comfortable and relaxed feeling. For me, the Nimbus 13 are too soft for competition, thus they are suitable for my recovery running. Heel strikers and underpronators would love them but I prefer the Kayano 18.