Welcome to the forum. I suppose the Line-X for the roof is new enough you're not going to get a lot of feed back on it. From what I've seen on line (and that's mostly a service center selling it) it looks like it'd be durable and essentially maintenance free. If it's true about it's heat reflecting abilities, that'd probably make it well worth the price. Please let us know if you use it and how it works out for you.
2000 Winnebago Brave SE 31B