I've got one on my EzyTrail.
The only issue I have with it is because the wheel axle is in line with the worm gear, when it is lowered down as far as it can go, it raises the height of the draw bar by a couple of inches more than a jockey wheel that has an offset axle.
When the jockey wheel is wound down as low as it will go, losing those couple of inches means I have to get the bottle jack out to swing the jockey wheel up after the trailer is connected to the car. The same thing happens in reverse when removing the trailer from the car, to get the jockey wheel to swing down, I have to jack the trailer up to get sufficient clearance.
Other than this inconvenience, it works a treat.
Cheers Marschy