The stages of both headphones is really comparable in size. It's hard to explain without having heard them.
Let's put it this way; the HD 800 makes my classic rock recordings sound kind of like they were performed in a huge concert hall (minus the echo and reverb). The Verite, while having large stage, doesn't do this when it's not called upon, but does have enormous stage (yet it does have some reverb and coloration of timbre).
Your original post asked for most massive and then "best," so my answer to most massive soundstage was the HD 800, and the best being the Verite.
The HD 800 has a SDR mod with the rug liner.
Yes, Verite is definitely the more colored headphone. I actually really don't recommend people buy ZMF headphones in general unless you auditioned or know what you're getting into; I know some people who barf at the sound of the Verite. This starts going into sins of commission/omission though, which is a whole other topic.