I am using the LCDVF and it works great with my 5D. It is much more economical than the Zacuto vf and is equally well performing. The form factor is in fact better than the zacuto model. Here is the website for the lcdvf: http://www.lcdvf.com/
I know the Z finder is more expensive, but one thing it definitely has going for it is the anti fog coating. I've been shooting for days in the cold with no fog on the lens even when I breathe right on it.