The blue cherrys feel abit lighter, and this is by some small amount, people who have 'evolved' heavy fingers after using the IBM Model M Keyboards, will feel that the touch is too light, especially after reaching the click point after which the keys will give way. But for people new to mechanical keyboards like I have will undoubtedly feel this is a good compromise for our less muscle bound fingers.
If you like your brown cherrys then the blue cherrys provide a little less tactile(touch) feel and much more positive audible(sound) response so you do not have to train your finger muscle memory on touch alone. Think of your car it is much easier to find the biting point with audio as well as tactile differences. The same goes with keyboards, however good typists will beable to use a brown keyboard still and really good typists will probably be able to use linear black cherry keyboards.
At the end of the day its also preference, the white alps have a slightly different tone to cherry blues and therefore some people like one sound over the other, I myself think the alps sound is better as xsphat just prefers alps and has an emotional preference of alps over cherry probably due to his initial keyboard scarring upon using macs alot and only macs and his disgust of pcs and so he hasn't come round to pc stuff as much ;-).
Anywho the Filco are expensive than the cherry because they have better build quality i hear that the key caps are made out of metal instead of plastic so im sure they will last much longer than your usual grade key caps. Some filcos are also able to handle n-key rollover and cherrys do not at least mine doesn't >_<. The overall cherry g80-3000 seems fairly robust, but it is designed for desktop use and not for being carried around. On another note you might want to consider the DAS 3 keyboards in the American format or blank european format, these keyboards use cherry blues as well and support n-key rollover, blank keys, usb hub, smaller form factor, dust magnetism(great for dusty rooms), geek/cool factor