While I can see some value in relative paths I have never found it an issue when moving sites between domains.
My solution is to export the database and then do a global replace on the resulting text file (no SQL required) i.e
replace 'http://myolddomain.com' with 'http://mynewdomain.com'
remember to unzip your db export file and open it with a text editor as a plain text (not sql) file. If you try to open the file with any kind of language recognition or specific formatting it will likely take an incredibly long time to open the file or use up all your memory and crash your machine. I recommend notepad for windows and textedit for mac for this job.
Save the file and then import to your new database. All references to url paths will work without the need to edit each and every post/page.
Just my 2c.