A postagem no blog do Opscode que introduz o modo local aponta a única diferença :
A note about chef-solo
chef-solo still exists, and this obviously has some overlap there. In most cases where you are using chef-solo, you will be able to use chef-client -z in its place, since chef-client has all of chef-solo’s features and more. Only if your recipes specifically test for :solo mode will things be different, since chef-client does not set this variable.
A menos que seus livros de culinária dependam de :solo
, eles serão substituíveis.