I would never again fit a wireless one. I found that my LED light affected it, then some traffic lights sent it spinning at high speed and I finally went for the Astrale Cateye (now obsolete). My wife persevered with wireless and we bought her the upmarket Cateye one (it grudgingly cost me £70) to replace the cheapy ones that both of us had. A year later, despite interfering with her front light, it finally stopped working. New batteries fitted, spent an afternoon attempting all sorts of repair and then decided it was as dead as a Norwegian Blue. So, my experience -a waste of time and money. My wired Cateyes (I have 2) have worked a treat for over 2 yrs with only a battery change.
Edit: Cateye Astrale and its replacement (can't remember name) work off the rear wheel and crank allowing speed and cadence to work on a turbo.