So, I just did a quick look at Johnson. Whew! So much happier with Guice!
https://www.youtube.com/watch?v=zx54PFMOgcs
Sure, Guice highlights have him running through big holes, but there are also quite a few where he runs plunges forward for yards when the play calls for it. Johnson, on the other hand, when the LOS is clogged, comes to a complete stop at the LOS in order to dance left or right before resuming forward movement.
All of Johnson's highlights have him making big runs untouched or dancing in the backfield. Guice just moves forward.