We use the eBay Escape cover on our 17B. It's a perfectly acceptable cover, although lightweight and porous, obviously to allow moisture to evaporate. It has done a good job of preventing dirt and grit builds up over winter here. While we don't notice any water spots after using the cover, it's rain and snow only, not a neighbor's sprinkler. And the cover is actually quite durable, now heading into its third year. You will get small nicks and tears, regardless.
Hope that helps.
To everything there is a season ...
2015 Escape 19: Escape Goats
2011 Escape 17 (previous): SittEscape
Honda Pilot 2011