Yes, definately.
Started with a good Acer14", went to a better Dell 15". Then to a great AST17" (Anyone else remember the AST 7L ?)From there I went to a Viewsonic P775, talk about clarity!! This was the best monitor I have ever owned.. I got the bigger bug and sold the 775 (Sad sad day...) and got a Viewsonic PS790 (Which I currently have.) I like it but the 775 had a clearer picture to me. I do like the 1280x1084 85mhz and 32bit color I have though...
For my eyes if it is slower than 75mhz I see a constant flicker. (I can see the flicker in a flourescent bulb, wierd eh?)
So yes it does make a huge difference to me anyway!
Rob