What benefits to expect from tonearm upgrade

Dear all,
Seems that it's time to upgrade my 5+ years old ortofon as212s arm.

To be honest I am quite skeptic on the benefits of tonearm upgrade based on some demo that I listened to. Unlike cartridge or table.

If, for example, I upgrade to $ 5,000 or more tonearm, and say it matches very well with my cartride (lyra kleos) and my table (TW Raven One).
Is the benefit audible? In what way?

Thanks in advance for any advice
I made the same upgrade as Jperry, (i.e. upgraded from a Rega (RB 900) to a Basis Vector M3 tonearm), and the upgrade was well worth it.
The noise floor became really much blacker and the bass response was deeper and tighter, as well as the benefit that Jperry noted.
Well worth the cost IMHO.
Just out of curiosity are you upgrading just simply because you want to or is something wrong with your Ortofon?
I am happy with my ortofon, just wondering if it is really worth it to upgrade to a more expensive one, based on my experience cartridge upgrade proves the best audible improvement after turntable upgrade.
Puting arm/cartridge compatibility aside for a moment....
It would be interesting to have some more comments when we talk about "upgrades".
Most of the time we mean differences(that we either prefer or not) and yes, tonearms sound different from one another.
I'd really like to listen to a tonearm that will trounce a rega rb300 (in every respect) for example.I've tried many tonearms and all were different.