The only mods on my r100gs were a proper side stand, more powerful headlight bulb, and got rid of the oil cooler the a mod to stop the oil leak.
The main mods done to my dads 990 adv were lighter silencers, big panniers, and soon a side stand mod the rest of the bike
The main mods I have seen done to the 12gs is a shorter rear shock, lower seat the shorter centre stand, as most people find the seat hight to be to tall.
suzuki gsxr 600 srad sound fun bike
bmw r100gs i sold as it be came to unreliable.
road legal stomp pitbike sold
Klr 650 the worst ever made
Honda xl125rc powered by a cg125 block fun wee bike