Hello. I am the Canadian! LOL! I own three Excals and the only wheeled xbow I would and might buy is the Ten Point but I would find it diffcult to get over the price to get a Ten Point with a trigger as good as my Exals. The awsome thing about Excals is that I've never had to take any of them to a shop for anything at all in over ten years (might be 12 or more) of ownership. Sooner or later a wheeled bow has to be into the shop. Other good things about Excals is they are light, not too expensive, no options to buy, they withstand a dryfire (ten point has safeties for this purpose), its the easiest to reserve, great customer support, etc.
Cocking the Vixen is breeze for my wife with a rope cocker so I suspect your dad will have no issues.
Bottom line is that if you don't get to shoot them then you can't make a sound decision. I never shot my first Xbow which is the old Exocet but I never looked back. I don't know if the Vixen was available at the time but I would have bought it had I'd known about it. The Vixen is more than fast enough, extremely accurate (it is often used in 3D) and has even taken moose. What more can a man ask for? LOL!
BTW, welcome to the forum!