How to identify newer model of the aluminium Cinema Display HD?

[HoreaG]

On August 7, 2006 the Aluminium Cinema displays had a silent upgrade that boosted the brightness and contrast ratios to 300/400 cd/m2 and 700:1. The last Cinema displays are still desirable [...] having a true IPS 8-bit (no dithering) fully back-lit panel and slightly higher brightness than that of the newer Apple Thunderbolt displays,

Says the Wikipedia https://en.wikipedia.org/wiki/Apple_Cinema_Display article in a footnote refering to the 20", 23" and 30" Cinema Displays. (A1081, A1082, A1083)
Unfortunately no source is given for this claim.

My question is, how do I know if I have the silently introduced newer model? IPS sure is a fine thing and a almost double brightness and contrast also do not hurt.

 

[chrfr]

At this point they're all old enough that the CCFL backlights in them won't be putting out anything close to rated brightness so this will be effectively impossible to track down now.

 

[HoreaG]

I still would like a 30" Cinema Display with an IPS panel. (Although I dont know what the technical advancement these days is. What can I get in that size and at what price.)

 

[Chucks4me]

Only way to identify the late model is checking the serial number.
In regards to display, the difference is huge if you have both versions next to each other.

 

[HoreaG]

Well, do you know with which serial nr. the transition from TN to IPS occured?

You mean the difference between the TN and IPS models? Yes, that I can imagine. But I dont know how the IPS model compare to modern (not necessarily Apple) monitors. I am simply not informed.