Fidelity Research FR-64x

Stainless steel is very heavy. Magnesium, Titanium, aluminum are all much better. 

Why are you guys guys interested in these super high mass tonearms? 

I posted because I have the 64x, mounted on original Pink Triangle.
   But they both sit languishing on sidelines for several years and 
I'm contemplating to keep or sell. I miss playing records but am
happy to spin cds for now and not sure if I'll ever get off my ass
and dust off the Pink and all my records . 
  chakster...it's definitely the 64x,black, and marked "silver inside
leads " on the barrel.  I bought the Pink Triangle for $150 locally in Hicksville LI back in the days when you could find stuff in Newsday classifieds almost everyday.
The guy I bought it from kept his arm but hooked
me up to another guy for the Fidelity Research, for another $150
I think,and  Grado cart. for $100. Not that I know a whole lot more
now,but I didn't really know a thing then, but got lucky with everything
I bought ,all used. I had bought a pair of Quad 57s(also via Newsday) from a guy
 in East Meadow who turns out to be Mr.Tennis here on Agon,Roy
Harris,who also wrote for Audiophilia ,and used to occasionally
write letters to The Absolute Sound ,strongly opinionated letters
that made an impression on me as a newbie. Anyway,I digress.
  The insertion of the Pink Triangle w/ FR arm made a big splash
and set me up for great music on the Quads. Long story later, Quads
long gone and belt not holding on to turntable,I dropped out for 
awhile until getting started with cds. And that's where I'm at now.
 I think if I could wake up tomorrow and my turntable would be all
set up like a good dream I'd be playing those lps again, so maybe 
this dialog will inspire me . Glad to hear your responses.....

Why are you guys guys interested in these super high mass tonearms?

Synergy with vintage carts (as mentioned), and of course heavier modern carts (Sensitive Sound for example at 20-23 grams). Not to say heavy = good by any means, but it happens to work well in some cases.

@offnon57
Well at $150 on the 64fx, you got an absolute steal. That arm should go for $1K+, easy, if in good/clean condition with original counterweight and silver internal wiring. More if you have the original head-shell. Plus for most low-ish compliance MC cartridges, it’s hard to imagine any $1K used arm options, and new arms sub-$5K (!), matching that FR64fx in performance and build quality.

I need to get a Clearaudio arm board cut so I can use mine again, especially since I have an extra Koetsu to pull out. It was a joy to use; silky smooth action. I currently have a Graham Phantom Supreme 10" ($6.7K new) and Clearaudio Universal 12" ($6.5K new) mounted; I expect this FR64fx should easily compete with (if not beat) them.