Initial impression:

WHM feels like the least disrupted of the healers. SCH seems like it's going to be more bland/boring regardless of damage output concerns, and AST is somewhere between the two in terms of discontinuity from 4.x to 5.x

Yet WHM mains tended to be more likely to looking for some disruption/larger changes, while SCH and AST mains seemed to want less.

So in the end, WHM is more WHM-ey, which is good or bad depending on how much you like it before.