the place i worked at switched from the lights to the mirrors after 3 years because at times the lights wouldnt work right so you would check, finish the hand, flip over your cards and have BJ, which killed sometimes 10+ cards on a full table taht should have still been in the shoe. they occasionaly get stuff stuck in them giving false readings at times, and if a wire gets unplugged, they will show green or red lights at all times, its great as a player for a dealer to check, flip a supposed blackjack and end up with 15/16 i love seeing that malfunction
chris