The amount of time it takes to run the Design Migrator varies, depending on several factors. Please keep these factors in mind when you select the sites and options to suit your migration needs.
• The number of sites you choose to migrate at once
• The number of pages within each of those sites
• The number of lists, and the number of views in each list
• The number of options enabled
On average, it takes approximately two to five minutes to migrate a single site, but that depends on all of the above factors. CorasWorks recommends that you migrate no more than 100 sites at a time, depending on the number of pages and complexity of your sites
The single option that has the greatest effect on performance is Update List Views. However, this option only needs to be selected when migrating a site that was just upgraded to SharePoint 2007, and only the first time the Design Migrator is executed against that site. When using the Design Migrator to update the design of an existing 2007 site or to deploy web parts to an existing 2007 site, this option should be turned off.