My wife and I did, we live in UK and employed a Canadian company. We wasted a lot of money and got two rejections, plus we did most of the work ourselves anyway. In my opinion they're a waste of money and time, they left important information out of our application. We applied a third time by ourselves, still awaiting a decision. If your application is normal and not complicated then do it yourself as the forms are straight forward and are explained on them how to fill them out. The hardest part is your SOP/letter of explanation so make sure you cover everything in it. There's a lot of information on this forum, I have found the people here very helpful so have a good read about the process and your options good luck. ;D