In my opinion I think the GN NetTest 4000i is the best most reliable OTDR. Been using a couple of them for 10+ years and they are rock solid. Legacy Fiber Optics http://www.legacyfiberoptics.com/ sells them refurbished for around 4k depending on the bells and whistles.
This is CABL.com posting #357218. Tiny Link: cabl.co/mbE5K