The free DLC for 3 million credits is your friend. Take advantage of it, or suffer a lot of grinding against weak crap for money and healing items which you will be going through like water. Speaking of healing, you have full control over it this time. No more of that "it'll activate some % of the time until you get it up to 100% activation" crap. Also, Nepgear's first skill is badass and can deal major league damage like that one Neptune had, but with no area effect. It will save your ass a lot early on as being under leveled for boss fights is a real bad idea and you don't get any extra exp for beating them at a lower level either. And don't even think about fighting those powerhouse monsters that now stand in place of the lurkers. They are tough as nails, and you are not. Especially Compa. She's got absolutely horrid physical defense. The best tactic with her is to keep her far enough from enemies to avoid being ganged up on (and they will gang up on her) but close enough to heal people.
Ah yes, speaking of battles, Nisa is playable without having to pay to unlock her for fighting like last time. I gotta say that her addition has made things a hell of a lot easier on the rest of my crew at the time you get her. I'm breezing through most of the enemy lines now. Though they seems to love the paralyze stat affliction. Annoying, but I have magic and items for that. Plus if you can quickly take out the ones that do that in the first volley, it'll be no problem at all.
Also, Nepgear has a very similar voice to Aurica~! <3 ^_^
All in all, this is my game of the year it seems so far. It's very easy to see why this game's LE smoked the competition in sales. The only game I can see giving it a run for it's money for me is Agarest 2.