We've done a number of moves in the States over the years with professional (Mayflower, North American, etc) movers. We have always learned to add an additional 7-10 days to each "estimate" in terms of how long it will take to get our things. On our last move from Texas to Ohio, the movers promised to have our items in about 14 days. Realistically, it ended up being 3 weeks from the point of loading the truck until delivery of our things.
In any case, what sorts of time frames have you experienced if you've used professional movers for your relocation abroad? A few cold calls around have given me estimates of anywhere from taking 4 weeks up to over 2 months until we receive our items after a move to the U.K. I know there's additional issues of having our items clearing customs and working with essentially two different "removal" companies. But what have your experiences been with professionals?