Rush is not the first of it's kind, the first one opened at Knott's Berry Farm as a prototype. Xcelerator was the first Hydraulic Launch Rollercoaster to be made by Intamin AG, not Top Thrill Dragster. All rides are never 100% perfect, remember the people who build them are only human, and cannot guarantee they will work every day. It was just unfortunate that Stealth, had to suffer lots of downtime.