Unger and Waterfed Pole...
HA HA HA HA HA HA HA HA HA HA HA HA HA
NOPE!
Unger were very, very late to the waterfed pole party, and even now have not got their products right. They just don't 'get' waterfed pole and everyone knows it. They are about 8 years behind the market leaders.
Look at that silly trailer you mentioned. Firstly its HUGE, you'd need some big powerful (and expensive) vehicle like a warrior or something to tow it. Secondly it's a trailer, with all of the inconveniences that means (eg trouble parking, reversing, storing etc). Why on earth would you buy that, instead of a van mount? You wouldn't.
And then, it's not even their own product. It is made by a company called DiBO for pressure washing, and adapted by unger for window cleaning:
http://www.dibo.com/en/pressure-washers/on-trailer-skid/high-pressure-trailer/jmb-m/jmb-m-20018-tgAnd the price - it costs a cool £12,000 plus VAT according to the window clean centre!!
You could buy a lovely van with a top-notch system for that money.
But that trailer tells you all you need to know about Unger and waterfed pole. It is absolutely a typical example of unger's efforts. They just don't have any understanding of how real window cleaners use it in the real world.
Unger always used to be the king of squeegees and hand tools, maybe they still are. But as far as waterfed poles go they haven't got a clue. That is all.