I have a few of the 560-IIs, and for off camera use they are fantastic. Powerful with easy to use manual controls. There are far better choices for on camera use though (no TTL, auto zoom, etc).
The 468II looks to be a great on camera flash, but the limited controls make it look like it wouldn't be fun to use off camera.
They're different flashes for different roles, pick the right one for how you intend to use it most.