or the "flow" is not as good....
Yep, the response-time of most LCD's-screens is not high enough for fast action-games - although there are some new out that do that trick.
If you want a really good one fast enough for Quake-like action you have to spend about $1000 though for a 17" (which is appearently the same size as a 19" tube monitor) - well,I wouldn't spend that much on a cab for the monitor issue, but best is to try the LCD with the fastet MAME-game you can find to see if you would be satisfied with it.
By the way, just wondering, we call these displays "TFT" here, is this term not used in the US