I had a pair of Calgarys about three years ago - quite comfy but they only lasted a couple of months and the quality was horrendous. I now have a pair of Canyons and so far they are fab. I've had them since May and I work as a groom so am wearing them all day every day, but so far there is little wear in them and they are so comfortable.
Try them on in the shop and see which one feels the most comfortable. I have either Canyon or Quebec boots, I can't remember which they are and they are very comfortable and I can wear them all day. They get hosed down twice a day to remove the clay mud before I get in the car and so far no leaks. They are fairly warm, however I can see me moving into my fur lined joddy boots for riding and yard work if the weather gets any colder and only using these boots for turn out / bring in.
I think it depends on what you want them for. I have the Calgarys and have had them 6 months so far, very pleased with them. I keep them for riding only though as I wanted a boot smart enough to wear for small competitions etc, (with my wide calves there is not much choice).
If you want a boot for general yard duties I think the Canyon would be a good bet.
I had the Calgarys and they were brilliant....until the bleeping zip started to unzip at the ankle! So, because the fit was perfect (wider calves...) I put it down to a dodgy pair, but the same again happened. So I went with the Canyons, and they are superb!
I got my Canyons in Nov 2011, still totally waterproof and I wear them every day to the yard. My only criticism is that they drop quite a bit, and the inner lining around the heel / Achilles ripped on my which can sometimes rub (99% of the time they are fine). Very hardwearing boots so far.