There is some good info on this thread. I would definitely get out of the Kayano, unless you are a heavy (200+) runner. I don’t mean to indult the shoe, as it is considered the Cadillac of running shoes, but it is just that: big and heavy. I was looking at it one time, and the guy at the shoe store steered me clear. He said that it was for big runners who need a lot of support and cushioning. So if you are not really big, and need a lot of support, some free speed can be had by switching out of the 14oz Kayano and into a lighter shoe, which would be almost anything else.
I think that there is some confusion as to what makes a racing flat a racing flat. Generally, they are extremely light(under 8 oz) and have a very short life. If you aren’t competing for money or a spot on the podium, you’d probably do better with a lightweight performance trainer, like the DS Trainer if that is your style, or maybe the Axiom 3. I prefer the New Balance 903. Weighs about 9 oz, has good cushioning, and feels like your running in somewhere between slippers and nothing.