Mick W can you really go backpacking in Inov8 318's? Aren't they a running shoe?
How tough a terrain have you been over in them?.
David, as one of the folk whose not been impressed with the 390s, I'll say that I love my Roclite 315s and have done a lot of backpacking in them, in the Pennines, Lakes and Pyrenees. I guess it takes a bit of getting used to, so maybe best to do some rough day walks first, but yes it's perfectly possible.
It was that experience that made me think the 390s would be good - after all, regardless of the 'paragliding' label, they have the same sole unit as the 315s, so it seemed reasonable to expect they should just be a higher-cut, waterproof evolution of the 315s with the same performance, but, as I've posted elsewhere, I've found the fit to be sloppier and less supportive. I'd happily take my 315s on far rougher ground than the 390s, with or without a load.