I found having high renegade or paragon paid off alot. I was an Infiltrator and had chose when I reached tier 4 to bump whatever my renegade and paragon were so I had full paragon and half renegade by the end of the game. Pretty much having the quick out to say something to defuse whatever was happening saved me many times. From Zaeed, Tali, and the Jack and Miranda beef.

I did miss the amount of customization the guns had in the first. But I can't say I was too pissed about it either.