I have this one:

http://www.masherz.com/products/sigm...dtscadence.htm

It's wireless, fairly inexpensive, has cadence, and I LOVE IT.

I love the cadence meter for many reasons but mostly for the same reason bounceswoosh does. I use my energy more efficiently with cadence than without.

I won't get another computer without cadence. If you don't go out to eat a couple of times, you have the difference in $$ between a computer with cadence and one without (Sigma anyhow, not sure about Cateye but they are generally more $$ than Sigma).

What type of riding are you doing? That might make the difference as to whether you would use the cadence feature or not.