European lamps are just better quality. Of the lamps I have used, only the Reeflux are Pulse Start. XM and others are Probe Start. Pulse start lamps and electronic ballast work better together. I have had Coral Vue DE Lamps go bad in 8 months and lost half of my SPS because of it. If anyone else knows of any other Pulse start lamps please let me know? A meter is the best way to check lamp life.