I had to deal with Wheelies after my road bike got damaged at work. After many e-mails/telephone conversations over a few weeks trying to get a replacement frame, I agreed to a frame/forks/headset/seat post package that wasn't quite like for like but I thought would be a good substitute. The delivery turned up, the frame was marked, there were no forks or headset and the seat post was wrong. So I called them, was met with mild indifference, so sent the package back rather than hope they would sort it out - 5 weeks at this stage.
At this stage I phoned M&S and stated Wheelies were unable to provide a suitable like for like replacement so they told me to get a quote from my local bike shop including build costs. I did this and the cash settlement I received was about £150 higher that I would have received from Wheelies.
I have used Wheelies to buy an Orange 5 for the wife using a corporate discount and some other bits and they were great for that, but you get a very varied service depending on who you speak to on the phone - the custom build guy was great but sounded a bit overloaded.