I have only rode the Hellrazor a few times now but I will give my first impressions. Keep in mind I am no expert so feel free to chime in if anyone disagrees. The Hellrazor is narrower and has more rocker than the Futura but surprisingly still grovels well. With more volume forward and less rocker the Futura probably grovels and paddles better than the HZ but not by much. The Futura is more stable in my opinion with the HZ being more fine tuned for better waves and high performance. The tail on the Futura is incredibly thin tho so that keeps it really responsive. IMO the Futura is a potential one board quiver for 2-6ft surf...I used it everything while in college and it did really well.
I had the HZ in some 3-5ft hollow beach breaks over the weekend and was so glad I was on it. The additional rocker and thinner profile helped me make some late drops that would have been tough on the Futura. I am really looking forward to getting on waves with shape so I can do more turns as so far I have only been surfing beach breaks (closeout barrels).
Overall both are sick boards and I think it depends on your personal preferences and quiver. The Futura will always be a favorite of mine as I rode it for over 5 years but I have to say that when the waves get good I will be grabbing my HZ. Futura probably excels in 2-5ft open faced waves with the HZ in 3-6 ft steeper waves. I hope that helps Custom and thanks Chris!