RE: What's the best bow?
Depends on what you want to spend and what you want to do with it. You mention the Guardian. There's also the Drenalin and Vectrix---all the latest and greatest things to ever happen to archery---or so it might seem. Also with prices of about $700.
There are a lot of bows out that can do the same job for a lot less money.Two that seems to be hot this year is the Martin Bengal ($400)and Pantera ($479)with the easy drawing MPro cam. Personally I like the Pantera with Nitrous X cams.
My advice would be to not take any advice at face value, but get out to shops in your area and shoot every bow that they will set up for you. Make a list of your priorities and compile a list of the bows that meet your desires. Then buy one.
I would say that Diamond is made by Bowtech, Mission is made by Mathews. Pretty good bows at about half the cost of their parents. Lots and lots of bows.