Refresh rate is 144 Hz, which is the only number that can be trusted. The 4 ms number indicates response time, which is 90% marketing since response time isn't measured in any standardized way. One company can claim 4 ms response time and another one 2 ms with both being practically the same. The only way to know would be to check out reviews on trusted web sites like TFT Central, but they only have a limited number of monitors reviewed.
Had a 1ms acer TN panel monitor which had so much ghosting that you saw every line of text doubled as negative when scrolling...
Also had a 5ms ips panel that was totally fine but became a little bit blurry when moving the camera swiftly.
I definitely prefer the little blur over ghosting!
Also this response time values are only for Grey to Grey, not for colours so it's indicating nothing basically for every day usage.
Look for some professional reviews like prad or tft central etc to get an idea what is good and what is not.
I have a Dell aw3418dw, 3440x1440 ultrawide. Ips panel, 4ms response time according to the specs.
It's a little blurry but there's no ghosting.
Only thing I don't like is that if your game has a clear, blue sky and you move the camera, the image will become a bit too "sharp" and there will be some moving banding lines...
Only game I came across this was the Witcher 3 and some hairpins in dirt rally though