Hi,
I have a Toastscan and have used it with many different monitors. Curently I am using a 19" CRT monitor and it works just fine. Obviously the image is a bit "Pixilised" but that is simply because the resalution of the Amiga is very low. and the Toaster/Flyuer has a default low resalution and canot be changed.
I have Tried my Toastscan on an LCD and it works as well but remember the LCD monitors have one naitive resalution usualy 1280x1024 and just like on a PC if you use anything lower like 640x480 you get a so called "blocky" picture, the same goes for the Amiga output you will see the same sort of thing.