I have spent significant amounts with them over the years with varying results.
It seems regions, number of entries and size all have an effect. I spent 3k with them once on one add on one page. Never got a thing, oddly enough not until the following year when I got 6 calls in 4months.
I then spent the same budget 3 years later but on 5 smaller adds across 5 categories. Results were much better about 20 calls through the current year, however many were the wrong type.
I then ran a company in Fulham for two partners for 6 months where they had a full page spread in the "A's" in 3 books which generated approx 10-15 calls a day.
It was never viable for me but most certainly was for the Fulham based company.
The key is to get your name under as many noses as you can as many times as you can. Therefore consider your budget in respect of the local rag.
You may well get a great deal advertising in there every week of the year which could bread familiarity and confidence. This would also fit the good advertising methods.
The ideal is of course both, but who can afford that.
Remember there is 139 ways of advertising a cleaning company (so I’m told) guess there is a lot more options to play with yet.