Grace F-9E Ruby or Nagaoka MP-500?

Hello, I am new here and it's my first post... (have been reading the forum for a while and benefited by a lot of information shared by the members)

Currently using Clearaudio TT with the stock tonearm and MM cart, and now thinking a cart upgrade.

I have seen a lot of praise for Grace and Nagaoka carts here, and noticed used F-9E Ruby (good condition) and new MP-500 are selling about the same price range on ebay.

If to choose one, which would be a better choice?

My other gear includes a solid-state phono (MM only), a 300B SET amp, Lowther drive units, and a powered sub.

Thanks!