I've seen both then karcher from guttercleaningsystems and the et system. I think the et system would be only really suited to big jobs. Buy the time you would have got the big vac out and set up, you would be half done with the smaller units. However the more powerful vac will get rid of turf easier, but not instantly. If you get any build up in the down pipes then the only way of handling that is with a lance pressure washer or a ladder, a vac just won't clear a down pipe, had one today completely solid for about a foot down.
Simon.