Quest Elite Rolli - roll out awning

Just been looking at these today.  wondered if anyone has had experience of them.  I have always been concerned about leaving a more substantial bag awning on the awning rail when travelling etc.  Just wondered if anyone feels it could put excess strain on the awning rail and could be detramental to the 'water tight integerity' of the caravan.  By using such an awning would it invalidate and caravan warranty (mind you they would need to prove it was used, I suppose).  

These type of awnings are attractive, but it just makes me wonder whether they are really a problem in a bag for the caravan?  For anyone wishing to go down this route, they do look nicer than the Fiamma and Omnistor equivalents - this one looks a lot more flrxible too.

David

P.S. For anyone who wants to look, they are HERE.