I recently picked up one of these beauties for an absurdly low price. I am very impressed with this unit. Not only does it sound very authoritative with the HD 600/Equinox combo; it also makes my B&W's absolutely sing
It seems to have a much more musical quality than my old SHA-1 although it's been a bit so I'm just going on memory. It pleases my ears more than the Headmaster it has replaced.
It's the current installment in my long line of headphone amp extended auditions
It's going to be around for awhile due to it's synergy with my speaker system.