The placement of reservoir right below pump intake (using big diameter hose) is indeed very important. My water cooling systems with such reses fill and bleed within minutes and pump performance is improved. Read this for details:
http://www.procooling.com/articles/h..._with_h2o1.php
Pay close attention to the NPSH discussion and the link in the article; it IS important (esp as we move to higher end pumps)