Why do you want to ruin your gameplay by power leveling. It only takes about 18 hrs to get to level 30 for PT2 with a second character (since technically your first time you want to watch the scenary and get use to all the enemies and stuff). So in under 48hrs you can take a character from lvl 1 to lvl 50.
You power level and in a matter of a few hrs you are already at lvl 30. Where's the fun in beating the game very quickly. Take your time as getting 4+ characters to level 50 is very fun but doing it in just a few hrs will ruin it.
Take your time and do it legit. More enjoyable.
XBL GT: xXxwilmer007xXx | http://www.youtube.com/user/wilmer007 In CoD you USE Killstreaks, In BF you ARE the Killstreak