I have a few Hagens, and they're alright. They can be a bit of a pain to change, since the Vision cages I have don't really have the tray that you can just slide out, and I don't really like the bottom grate. Poop just tends to get stuck to it, and it's even more tedious and harder to clean than a newspaper at the bottom of a cage. It doesn't help that I always worry about my birds getting their feet stuck in them, since even though I have larger cages for my tiel and lovebirds, the grates are a lot narrower. I've removed the bottom grate from all of my Hagens cages.
As a rule of thumb, bigger is always better for most birds. Just make sure you're getting the right bar spacing for a canary, and be wary of the perches they provide with the cages as well, as they often come with dowel perches which aren't good for a bird's feet.