Is this legit? Android 6.0 Marshmallow ROM for HTC Desire Eye...

Here's a link and it seems to have multiple people saying it works. I'm weary to try it just because it makes me do surveys to get the files...
http://www.marshmallow.website/2015/...-eye-6715.html

I'm looking to accomplish a root without modifying the system, as mentioned on this website, but I need to update to 6.0 first.
http://www.xda-developers.com/chainf...ifying-system/