What are the most balanced relatively neutral cartridges at each price level ?

Agree with @jperry - Ortofon, other than the SPUs

I once kidded a friend when I recommended that he get a Van Den Hul Colibri cartridge--it is a very fast and lively sounding cartridge which is exciting to hear, but, I probably would not want to live with it--which is why I wanted someone else to get it so I could play with it.

The Colibri’s are absolutely like that, and it can be an exilerating experience at first to someone attuned to the warmer / sweeter side of things (me). However, they’re also very susceptible to sibilance. The extreme stylus and its need for extremely precise alignment are often blamed for this - however I’ve had this type of stylus (VdH / FG) on other cartridges without ANY such problems. I suspect the Colibri’s unique mechanical design is what’s actually to blame for sibilance - wonder if anyone’s tried damping it mechanically with blue-tak or the like? It also doesn’t surprise me that VdH carts are commonly paired with VPI tables (often darker sounding).

I have an Ortofon Winfield and agree it doesn’t seem colored in any way in my system......(all Ayre with Vandersteens)

I had a Windfeld Ti and it was super. I sort of miss it, actually. Not sure why I sold it - the guy who bought it loves it! The older version (Windfeld MC) seemed a little more dry & lean in mids, but my system at the time (15 years ago!) was also a poorer match for this kind of "high accuracy" cartridge. Windfeld Ti would be my defacto "neutral-ish" recommendation at the $5K price point, but sadly its MSRP keeps creeping up...

I would also look at the new A90X. I liked the A90 a lot, too. 

I’m not sure why SME arms became a point of contention, when nobody in this thread has said anything negative against them. They are broadly respected.

Winfeld guys, not Windfield.  A wonderful cartridge.  

Windfeld, not Winfeld. Definitely not "field", though ;) 

https://ortofon.com/products/mc-windfeld-ti