I have a 1999 RX 10.9 in polished titanium. I found a great deal on one not too long ago. I'm enjoying it. My recent upgrade to it was to give it a new set of wheels (ROL D'Huez).
The frame was built for Mongoose in the USA by TST/Sandvik in Kennewick, Washington. the workmanship and welds are superb, and it rides and performs great.
The drivetrain is Shimano Dura Ace 7700 9 speed. I'm glad to read about other owners out there, as you don't often run into another one of these in the wild.