I bought this blower to enable me work safely at the bottom of a 6 metre deep well. As far as I'm concerned, it was worth the money for just that one job - although it will certainly be used again. I was impressed by how solidly and well-built it is, the body tube is absolutely rigid and the 10 metre duct means the outlet can be positioned far enough away to prevent recirculation. Obviously with such a long duct, there is probably some loss of throughput but it certainly produces sufficient airflow to allow working in a confined space and I'm sure the larger models would give ample airflow for larger spaces.
The unit is not too noisy if you are near the fan and quite quiet at end of the duct.
All in all I cannot fault this product and strongly recommend it (or one of the larger versions) to anyone working in confined spaces or requiring efficient fume extraction.