I used World First for transferring money for the first time recently. It's fairly easy to use and certainly saves you money compared to using a conventional credit card or High Street bank for transferring money overseas. Staff correspondence was friendly and quite helpful. Emails were informative with confirmations of the transactions attached as PDF files.
Downside? My funds didn't appear in my World First account until the next day, even though the funds were sent via Faster Payment at my bank (normally takes a minute up to 2 hours maximum). Other downside is that I discovered that OFx had a better exchange rate for the same amount of money, so I could have saved a bit of money by not using World First. In future I'll be more careful and shop around before using any money transfer service.
At the end of the day, World First UK Ltd could be the friendliest, most efficient company on earth but - like any bank or financial institution - they make their money simply by taxing your money in some way, not by breaking sweat producing anything themselves. So, in a time where many of us are struggling to pay our bills and make ends meet, it's a case of finding a company who will take as little from you as possible for simply 'handling' our hard-earned cash. In this day and age, 'handling' money doesn't even involve anything physical as it's just numbers being shifted from one website to another, all from the same office chair.