Does any one currently doing a PhD actually regret doing it? If so, what are the reasons for this? Cheers

'cause people are always complain about something its the human nature

Because all my friends were promoted to managerial positions while I was carrying books to school (studying for a PhD). I am still stuck in a low-paid post-doc.

If you want to make big bucks you should really ponder doing a PhD... and definitely not a post-doc in an university.