Back in the day, porting was quite the manual process. My first ever port was from Bhell to Rogers literally on the first day that porting was went live. It took over 2 weeks because the fine folks at Rogers dropped the ball and lost my number in their system. They kept blaming Bhell for not releasing my number and of course Bhell was adamant that they did. It took daily calls for more than 2 weeks before I found someone who knew his stuff and was willing to take up my case personally until it was complete. This motivated person took a couple of days to make it happen. Fast forward 12 years and with fully automated systems as long as the right information is supplied, the porting will work 100%.
Now this could be a useful peice of information to persuade people to switch, as pointed out by one earlier post.