Hi Ant,
We have just purchased the dragonfly with 23 foot pole. Also got the vikan ergoclean.
Yes great tools, over priced as usual (Just my opinion)
Results are good, the special microfibres cloths are expensive.
What it cant do... dont go into a building that has not had a first traditional clean. The idea behind it is regular maintenance.
The cloths last for a long time (500 washes) but not when actually being used. As soon as they get too wet the won't clean and leave smears. So you need to purchase a fair few.
We do alot of showrooms, office building and its gtreat for tall hard to reach places.
If you clean alot of corperate offices where they have board rooms as long as football pitches with glass partitions the the vikan ergoclean is ideal. Same cloths.
There is another thread if you look that I started, people have made themselves. Saved alot of money and the build quality is probably better.
I just did not have the time to collect the stuff and put it all together.
http://www.cleanitup.co.uk/smf/index.php?topic=103168.0Dave