i've found your deffinetely better with a water cooled turbo two reasons one you don't need to run cool down idle time, two your in the water so you have an endless supply of cool water.
superchargers run more low end torque while turbos run more high rpm horsepower. "generely" but as check300 said newer turbos with ball bearing setups and lightwieght impellers spool up at alot lower rpms than the older ones. The biggest cause of turbo lag is superheated air that can't atomize the fuel properly but with ample suply of cold water for intercooler turbo is deffinetly the more efficient forced induction if the two. my $.02