The best registry review product based on performance was measured by the pure performance increase the machine experienced after using the registry utility by itself.

First position was giver to Registry Mechanic based on its ability to purely increase the speed of the machine, unfortunately its very thin on features, however its performance more than makes for it. (read the registry mechanic review)

Following Registry Mechanic hot on its heals was Registry Fix. Because of the additional start up features that Registry Fix contains it may be a better buy than Registry Mechanic.(Read how closely it performed to registry mechanic here.)

In third position was Registry Smart, which blew away some of the more fancied oppostion once its more irritating features had been removed. (Read about how well this budget tool performed here.)