All other specs are the same. If it were you, would you go for the faster response time? Or the higher contrast ratio? I can't imagine I can tell the difference between 2ms & 5ms. Think my existing monitor is probably 8ms anyhow.
I figure since gaming is my biggest thing, 2ms response would be better than 5ms. And since my current monitor has a contrast ratio of 500:1, the 1000:1 (12000:1) contrast ratio would more than impress me.
Just the jump from 1440x900 to 1920x1080 should be nice. I suppose I could have waited for 1920x1200 monitors to come down in price someday, but... well I had the itch and had to scratch it.