I have a Sigma double wireless computer. I no longer use the cadence feature, however, but haven't bothering to remove it. I, too, like the clean look of a wireless computer. That said, I've often been very aggravated with trying to get the sensor lined up with the magnet. Because I transport my bike in my car a lot, it has a tendency to get jostled around. If I just rode my bike to and from my house, it probably wouldn't be a big deal. I've also had some trouble with the computer itself staying put on its bracket on the stem. The "locking" mechanism for it isn't very secure.

I'm in the process of building a new bike and I'm hestitant to use Sigma again. The price is right and the computer itself is easy enough to use, but there are just too many bugs with it.