How I conduct net research:
Step 1: get an update from someone I know asking me to update their Plaxo address book. Do so.
Step 2: Get interested. Contemplate asking Ian if he has used Plaxo.
Step 3: Google Plaxo sucks to find downsides of service.
Step 4: Find this laudatory post from Lifehacker, and read the negative comments.
Step 5: Decide against Plaxo.
Total time: 5 minutes.
UPDATE: A Plaxo guy called me out on using 5 minutes to judge the quality of a service, and I answer him here.