I fitted EBC ProLites to my FJ a while before I sold it with 132k miles on the clock, when the original s/s disks were getting too thin (at about 90k miles if I remember correctly). They seemed to be lasting well - they were a fair bit thicker than the originals and definitely improved the braking (even with braided hose already fitted).
The down side was the rust and the rattling. If they got wet in the morning they'd be going brown by hometime. Not a problem as it cleared with the first touch of the lever, but if you left them any length of time the pads would tend to fuse to the disks. Again not a huge problem - rocking the bike off the centre stand would release them.
The rattle though could be a little annoying particulary once the bobbins started to wear. One seemed to have worn more than the others on mine and I didn't seem to be able to source a replacement.
Having said all that I'll consider them for the GS once mine need to be replaced.
Phil