I think your current screen is TN.
It is very easy to tell.
Just look at it from high above or far below. If it gets darker(even inverts the colors at some point) or lighter, It is TN. In exchange for these bad viewing angles, you generally get a faster screen. Also my 144hz screen get brighter and the contrast changes between 60hz and 120/144hz. I am not sure if ALL 120/144hz screens do this.
If most of the colors do not change, but darkest colors become more visible from the sides, chances are it is a VA. VA panels have the advantage of having some of the highest contrast of all LCD based screens, but are not that fast(some pixel transitions over 20ms are not unheard of even when screens have G2G times rated at 6-8ms).
If it has minimal shift it is an IPS or one of its variants(AH-VA/PLS). IPS screens also tend to have something called glow(mostly in the corners) on dark colors and sometimes noticeable on bright scenes. This is because to keep prices down they removed the TW polarizers that they used to use to minimize this glow issue.
As you can see all screens have strengths and weaknesses. When switching from one type to another you may see the weaknesses, but with some time you may start to like the strengths.
I am not trying to discourage one type of panel over the other, but some IPS panels do have lots of glow, that I personally do not like(yet Sony has IPS TV's[years back and all] on the market that have NONE).
For reference the VA panel was at about 15-20 percent(forget the exact number) brightness because I do not like things too bright while the other one was at 100, but it did not help in this respect.
In a dark game, the screen just killed the details compared to its VA counterpart(again the VA was slower).
Color separation was also better on the VA(possibly from the higher contrast ratio, but this one is not that high).
I even have a TN panel I could take images of, but that is a job for another day. The camera is more sensitive than my eyes too, I tried to get as close to what I see. The cool color on the IPS screen(not the actual glow) is normal for WLED back lights and not an issue.
As for speed, this varies from person to person and most screens have some color transitions being faster than others. Check out TFT central for some examples if this. Also note that some newer IPS panels are getting very fast consistent speeds across the board.