I had a powerful4x4 one on the trol. The roos systems ones look identical. The actual build quality was quite good and apart from the fact that the mesh floor is "heavier" quality on the name brand units, I could not fault the unit. Where it was let down was with the quality of the paint. Of course I did not realise this until it was on the roof and rust spots started showing through after only about 3 months.
However if you aranged to get it spray painted again before it went on the roof, the price lets you be able to do this and still cost less than the name brands, then I would have no hessitation in buying one of them again.
For the 200 though, I have brought an alloy name brand one, as the roof loading on the 200 is lower than it was on the trol.
Cheers, Craig