I'm using a bog standard Dell 15" TFT with my falcon, I think it's a 1504FP, only about three years old. I'm not using the Atari VGA adaptor, I'm using one that was built by a Polish gentleman and that I purchased from eBay. Works flawlessly in all VGA resolutions. Haven't tried it with any of my 17" Dell screens yet, but I expect they'll work just as well.
It also works with the VGA adaptor that came with the Mono Monitor I bought from Compo a while back on my ST - although the display is Green-on-black.
