What benefits to expect from tonearm upgrade

I think the first question you need to ask yourself is whether a tonearm upgrade is the best way for you to spend 5K upgrading. It may well be, but maybe not.

I agree with Chayro in thoughtfully questioning where the investment should go. Your current Jelco-made Ortofon looks pretty good. The $5K level arms are certainly nicer, but your current platform seems solid. And don't underestimate the convenience of a removable head-shell, not to mention the tweaking you can achieve with shells of different mass & materials.

I haven't done too much arm swapping, but have had the following in my system:
Fidelity Research FR64fx
Graham Phantom Supreme
Clearaudio Clarify Carbon (temporary w/ Ortofon Cadenza Bronze)

I did a lot of cartridge swapping on the FR64, between various Benz/Ortofon/Koetsu. They were each very distinct in their sonics. When I transferred my Koetsu carts from FR64 to Graham (quite different arm implementations), they each retained their distinct Koetsu sound plus their subtle individual nuances. When I heard the Ortofon/Clarify combo (on an Ovation), again it sounded like what I knew/expected from that particular Ortofon model (i.e. excellent sound in the case of the Cadenza Bronze). In other words, the Clarify was much cheaper (and it looked/felt cheaper) than my usual arm, and that 2-axis magnetic bearing is a pain in the ass, but I didn't get the impression it was holding the cart back too much. I've also played with the newer Clearaudio Magnify (1-axis magnetic bearing), and I like that arm a lot. Seems to occupy a good spot for its price vs. quality, even with Clearaudio's outrageous pricing.

That said, the Graham and FR64fx have a quality and substantiality above what you'll get from lower price rungs. The Graham's adjustability is particularly superb.

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.