the main drawback with G is that if you take it with alcohol you could die if you don't know what you're doing. you must know your dose, and everyones is different, or you can take too much and pass out, or take too little and not feel much. also if you G out, but are still awake (which has been known to happen while on coke or amphetamines) than you could end up doing some really stupid and embarrassing stuff-get naked for no reason, roll around moaning and sounding like a retard, hump a stuffed animal (i've seen a chick do it), etc. it can also be addictive, but only under the most extreme circumstances.
GBL is cleaner for electronic equipment, at least that was it's marketed purpose. little did they know that it would turn into GHB in your stomach. and if you make GHB, than GBL is the main ingredient. GBL, NAOH, and water are the ingredients in GHB.
peace, outkast