We chose these guys from a range of quotes to do some work on our tenement roof, because they were quite a bit cheaper as they use ropes instead of scaffolding. We were really pleased with the work they did, and they picked up some odds and ends while they were up there which we hadn't spotted beforehand. They came when they said they would and got the job done well, so far as I can see. They're very busy, so you might have to wait a while for then to come out to quote/do your job, but I guess that's a good sign because it shows they're in demand.