Spent a bit of time as Whitebeard. He's exactly what you'd expect; slow, but with huge range and devastating power. In keeping with the frankly ludicrous feats he displayed during the War arc, he also seems able to take small hits without flinching, which helps his "beat" counter hit several hundred every game without fail.
After raising Whitebeard to level 20, I started trying the weakling trio. Now, I love Chopper, but... well, he got a raw deal in PW. He has no range at all and his moves are so slow and weak. Ugh. At least Guard Point is both well implemented and very useful.
Nami and Usopp are still only level 4 a piece, so can't pass comment on them yet.