I was in your position last year and its the best money I spent. What I found was it brought me gutter and conny cleans which I converted into regular cleans.. You need to check out how many of your competitors use it locally. If there are too many forget it as they will be at the top of the pile with feedback.. Feedback is Key to Checkatrade. I find that every time I have a drive at getting new feedback published My checkatrade driven calls rocket..
All that said Im fining that most of my Window work comes form Yell.