Another thing to take into consideration is the, hmm... sorry, but I lost the word here, but it is related to how well the TFT handles motion.
Considering the fact that most people buy scandoublers to be able to play games on their monitor, having a TFT which handles motion bad will, in combination with a TFT that isn't smoothing the screen when strecthing it out to be full screen, it will not at all be a pleasant experience if the TFT isn't suited for this.
Why? Because if it is not suited for this, not only will the TFT in that case strecth the screen making the pixels having an ugly ratio (if the pixels should be 1, 1, 2, 1, 1 it could render it like 2,2,1,1,2 in the process, looking really bad) and also it will become blurrish and even uglier looking when the graphics are scrolling.
So, like some have said, if possible, try out the screen before making your final decision.