Originally Posted by
rekmeyata
the wireless sending unit fries batteries about every 6 to 9 months thus you need to carry one in your seat bag just in case it goes out on a ride.
My Cateye Strada double wireless flashes to let you know which battery is low (head unit or wireless sensor.) It keeps working for maybe 2-3 hours after you get the low battery indication so you can replace it when you get home.
Wired is better if you don't mind the aesthetics of the wires. On my new carbon road bike I went with wireless due to ther superior (IMO) aesthetics.