Very accurate AfxToo... Only issue with the light sensors I can come up with is placement. If you go through the timing system like a "turtle" and hit a few LED sensors you could grab a few laps for others. In that way it is a Pain but you can limit that quite a bit if you set "minimum lap time" to nearly what you run on a typical race. For instance, if you run typically 5 second laps and the record is 4.8seconds then if you set 4.5 seconds for MLT then you will usually have little errors on others making laps. I have never seen issues with deadstrips aside from another car passing while in the same lane then the MLT works here too... The good news is that you dont require a "light bar" tower with which to crash into or get out of alignment.This article has a little bit about dead strips. http://www.infoserve.net/oss/slotcar/ds.htm
All timing mechanisms have pros and cons and all can be made to work reliably if you know what you are doing and get them setup and fully tested. I'd say about 85% of the tracks I run on are dead strip based and they all have been extremely reliable over the years.