This chapter returns to country-level appraisals comparing the distinctive features of the four policy advisory systems (PAS) and implications for the policymaking of different advisory system configurations. The book shows that the Westminster PAS has been significantly transformed over forty years and that its elasticity has been enabled by an administrative tradition that is pragmatic and highly instrumental. Several dimensions are reappraised, providing insights into the state of the PAS. There has been remarkable change in the four PAS in terms of the supply and demand of advice. Some advisers have become more influential; others have been relegated or their influence has fluctuated because of changing ministerial needs, competition from other suppliers and the turbulence of policymaking. The work of policy advising has evolved within the public service and though the increasing professionalisation of external advisory activity. Finally, there are the implications for the quality of public policy through the directions in which PAS have changed. Questions are asked about the effectiveness of advisory systems, the impact on public policy and what learning has occurred from managing PAS. Comparative analysis helps to understand the evolving architecture of PAS and the art and craft of advising governments.