I never thought these refresh rates would matter until I bought the U2412M, which replaced my TN panel Dell SP2208WFP which had 2 ms response time. But the thing is I'm not noticing anything in gaming, I mainly play FPS games like Crysis, COD, BF and kinds and also Watch Dogs etc, but I even played NFS Rival on it to see the difference, but I didn't notice any, I'm sure it's there, but it's just not visible enough to my eyes, if at all.
But what bothers me most is when I scroll down on an webpage filled with heavy texts, the texts and the lines always leave a ghosting, and it looks awful to my eyes.
You are not noticing any difference cause there actually isn't any. And you are confusing between response time and refresh rate.
Response time decides the input lag, ghosting issues, etc
Refresh rate decides number of frames per second.
Both U2412M and SP2208WFP has same refresh rate i.e 60 Hz so no difference in FPS
but U2412M response time = 5ms
whereas SP2208WFP response time = 2ms
technically they are both classified under Class 1 as I have explained in previous post anything <16ms is class 1 which means Less than 16ms / 1 frame lag - should be fine for gamers, even at high levels. So in FPS games you won't notice any difference.
But yeah when you scroll some heavy text filled webpage then it might lead to some visible disturbances , but is it actually a deal breaker?I guess not.