It doesn't flicker much when operating with electromagnetic ballasts and doesn't bother at a distance; with electronic ballasts, it doesn't flicker at all! About 4.5 minutes for maximum performance when using a magnetic ballast, with electronic ballast, two times faster warm-up at 2:20 minutes! Small size but performs quite well with a power of 70w and brightness of 5600 Lumens; it is a typical high-pressure sodium lamp from Philips, called Philips SON 70w, which is the simplest category and not as efficient as the higher models from Philips (SON-T 70w 5800 lumens, Master SON PIA Plus 70w 5750 lumens, Master SON-T PIA Plus 70w 6600 lumens, or SON-T APIA Plus Xtra 70w 7200 lumens, Master SON-T APIA Plus Hg Free 6300 lumens, meaning without mercury, and SON APIA Plus Xtra 70w 6600 lumens! As a good and well-known brand, I believe this lamp does its job; it will last for years since the average lifespan is 28,000 hours and will definitely last a decade or more!