Some of my friends and my pinball technician . LED's make them feel nauseous .Not sure why that happens. But personally I love them .
Back in 2009 I think when I did my first ever LED conversion TOTAN I had to use German LED's as no US company had the flex style LED in the color I wanted like turquoise or the Flux european hue . Now companies like http://www.cometpinball.com/ offer even the Flux style hue I like .