I got my cavision this weekend too. I was surprised at how much of a difference it makes. My worries about 6x magnification were unfounded. It feels just right. I did a few tests and I'm able to get perfect focus without any 'searching' about 80% of the time. That's significantly better than when just relying on the lcd screen.

The only downside to it, like with all loupes, is that getting the camera out of the bag and setup takes longer.

The biggest downside specific to the cavision is that there is no way to clip the loupe onto any kind of frame. The swingaway solution that they have is no good for me because I always have my camera on an swiss arca style L-bracket.
I'm currently using some flexible wire (paper clip style) tied to the loupe and hooked over the flash. With my eye to the loupe, it doesnt really move around.

What about those of us who wear glasses? I'm not sure whether I'll go with the Zacuto or the cavision.
Bruce yarock

I really like the Cavision and the swing away bracket. However, I'm far sighted and when I look through a viewfinder, I'm using the upper part of my progressive lenses, ie., the distance part, not the reading part which is in the lower half of the lens. So I am pretty sure I need the diopter adjustment. I bought a magnifying glass to see what would happen, and to bring it in focus for my eyes, when it's mashed up against my glasses, I need to pull it about 4" from the LCD, which is more than the Cavision allows for. There is some fore and aft adjustment on the bracket, but I'm not sure how much. Also, pulling it away from the LCD is going to let light hit it unless there's some sort of extension tube. All of which means I'm probably going to have to bite the bullet and go for the Zacuto, even though I don't like the way it mounts. I can't scrimp when it comes to focus.

Most people who wear glasses seem to be more near sighted than far sighted; if that's the case, the Cavision would probably work for you. To fit the 7D it needs a spacer, which they sell for a little more. If they had a diopter, I'd have already ordered it because I really like their bracket arrangement and the big size of the eyepiece.