Originally Posted by RobbieTunes

I don't use one, and have tried the Mavic, Planet Bike, and a couple of Cateyes. The other day, I spent $15 on a handlebar mount for my TomTom, and gave that up, too.

The Mavic was wirelss + wireless cadence, and never read a thing. The next owner said he got it to work.
I gave away the Planet bike, because it seemed a nice thing to do, for a novice.
The Cateyes were take-off's, which I couldn't get to work. Amani576 figured them out, so he can have them.

Several reasons against, from a curmudgeon guy who actually likes gadgets, too:

1) I like a clean look, so that leaves out the wired versions and a lot of older ones.
2) Eyesight, so that leaves just the big numbered versions eligible, anyway.
3) On a several group rides, I've seen people focused on their cyclos, and wipe out.
4) I hear "READ, darnit!" a lot on the same rides, from the same people.
5) I mash low rpm's, and I get tired of people asking "do you know how low you're spinning?" No, I don't.

Several reasons for, from the same curmudgeon:

1) There are some real clean new ones out there, everything's on the L stay, wireless. Acceptable.
2) You can alter the screens on some just to show one display, big numbers.
3) You can set the display to fade out after a few seconds. I'd like the lack of distraction.
4) Reliability is getting better. Some of my riding friends never have a problem.
5) On group rides, I'd like to pull at the pace they want. Sometimes, I get anxiety about going too slow, and drop the group.