I went through the same thought process before my purchase and this is what I came up with:
1 - The 1860NX has a 30ms pixel response time. That is important in gaming. The lower the # the better. The 1760NX (brother to the Hitachi 17" with the 16ms response) in contrast, has a 16ms response time.
2 - Brightness: 200cd/m2 for the 18". That is ok, but not too good. The 1760NX is a 260cd/m2, not the best...but much better.
3 - Contrast Ratio: 350:1 (1860NX) versus 450:1 (1760NX). This is important because the higher the contrast, the better the quality of the image. <-- Before a flame starts, this is not a technically sound statement, but is a general rule of thumb (IMO).
4 - The 1860NX is a little expensive.
5 -
In conclusion, the 1860NX is an O.K. monitor if you are going to surf the web or using word processing. If you want a good gaming and DVDing LCD, I say go with the 1760NX as it is one of the best if not the best out there right now. I didnt think giving up 1-2 inches of screen would hurt me, so I bought the 1760NX because of my gaming and DVD pleasure. I will review it soon, and let everyone know about it. If you have to get an 18", I would suggest the Dell 1800FP, as I have that at work (I look at network maps all day and game some) and think it is pretty good. Not as nice as my personal 1760NX, but not bad.
Thanks,
Mack