Originally Posted by
redeyedtreefr0g
No, a temporary light is fine, I don't mind pushing buttons occasionally to see it. I just don't want to have to carry an extra flashlight in mouth 
Sane people would just use a headlamp.
Originally Posted by
redeyedtreefr0g
I don't care if the computer has wires or not as long as there isn't any added inconvenience for wireless- such as having to replace batteries constantly. I assume wired versions are cheaper?
Wired tends to be cheaper. Wireless requires an extra battery in the transmitter.
Analog wireless computers can be prone to interference (including from LED lights sometimes), which can yield erroneous maximum numbers (like maximum speed and cadence). Wired computers and digital wireless really don't have this problem.
The Node 2.1 that I have is on the same batteries since from around April (and 4000 miles).
If you need cadence, wireless is a bit more convenient since you don't have to string a wired to the chainstay.
You want, in my opinion, one transmitter that handles both the wheel speed and the cadence.