We have just signed up - web only to start with. This package isn't too bad £400ish. The alternative is web and card (100,000 distribution with your details in a small box amongst dozens of other trades) working out at £750ish.
We are giving it a go for a few reasons, not simply to get new hits from their web site - by this I mean increasing credibility of our business (Joe Public where we are have heard of Checkatrade but may not know what NCCA is for example).