Tablet, mouse, does it matter? Neither one is the most sufficient! Even if one was superior, it'd be like relearning the game switching. Have you seen firebat92? He played mouse and was actually champ for some time way back when!
Also, I found a thread from 3 years ago which states this. It says, and I quote, "The purchase of a tablet or better computer equipment such as a mechanical keyboard won't make you any better."