yes mental force sux **** not worth it
some dudes it's fine veigar, leblanc, gragas, etc.
the tiny 3 ap you get will, after scaling, do less damage than if you were hitting with +3 AD auto attacks (plus the arguably bigger benefit of easier/more consistent creeping)
****ty masteries: havoc, mental force
sick masteries: reduced damge from creeps, increased damage to creeps, improved recall
edit: and yea summoner's wrath is pretty good. a MUST if you carry exhaust, pretty darn good if you carry ignite. 5 ad/ap is no joke for tight engages (and it also helps with creeping!!!!!!!!!)