We carry both, so my bias is on what I like... not what I sell... The zeagle has a life time warranty instead of a few years... And the zeagle is component design. I can remove the shoulders and replace just them, or the waist panel, or the bladder instead of replacing the whole bc if I have a problem. That also allows for very customized fitting, where we can take say, large shoulders and put them on a medium waist panel for the tall skinny person.
I much prefer the zeagle weight system, a one move action to dump both sides - while it a 2 step on each side to release the scubapro weights - and then - you've lost your weight pockets.
And as previously mentioned - the pockets on a knight hawk are virtually non-existent, and you have 2 big zippered ones on the ranger.
I also like the 2 tank straps on a Zeagle vs. one on the Scubapro.
But I find the ranger bladder very bulky. The knight hawk is more streamline in the bladder department. The ranger bladder was originally designed for diving twin tanks... and I'm a single tank kind of guy.
That is why I had Zeagle custom make the
Brigade for me... which is basically a Ranger, with an extra roll down pocket, but put on a more stream line bladder - much like the one on the knight hawk, it is also used on the escape, and the zena.
So you gave a choice between the two... when faced with a choice between two things - why not take the best of both?
http://scubatoys.com/store/detail.asp?product_id=ZeagleBrigade