Thanks for the input guys. I am no where needing more fuel anytime soon, and when I do, it will be a random trip here and there. With that said, 95% of my annual riding, is my normal weekend riding, and for that, the lighter, the better. That is what is making me lean towards having a very easy way to have the extra fuel when I need it, and not have it, when I don't.
For most of my weekend riding, its east coast single track..dodging trees every 3 ft. The less sloshing gas, the better. The KTM 300 EXC was supposed to become the dedicated woods bikes, and leave the WRR for more dirt touring, easy riding duty. BUT, KTM's being KTM's, it has spent as much time in not running condition, as it has running condition.