Changing the toe block changes the inboard toe. Increasing inboard toe in general provides more overall traction and makes the car more mechanically stiff. The downside of inboard toe is it can decrease cornerspeed.
Changing the outboard toe (hub carriers) is generally a mechanically softer change, and would be better suited for lots of sweeping corners. It also feels like a more subtle change.
The toe blocks also change the wheelbase of the car more than the hubs.