I understand that when migrating to a new site, even if done perfectly (page level 301s etc) that rankings will drop in the short term and each site will be impacted differently. I picked up the following comment and was wanting to get a few experts thoughts on whether I can quote this to my client:
"In our experience, even when 301's are correctly executed, we see a short term fall back (7-30) days and then about a 90% carry through after that period for about 90 days and then back to full strength. "
