My evaluation comes from my own biases, which boil down to: play the sort of cards and decks that lets everyone at the table have a chance to breathe, play Commander, and have at least a decent chance to do the thing that their deck wants to do
But what cards are particularly powerful in these decks
When I played my Jarad deck, I was impressed by how unbeatable Angel of Serenity was, so I thought itd probably be a good card
Nice, on curve, and can really punch your way to destroying problems
It takes any Vampire deck and gives them different modes of attack, as the -3 ability can immediately accelerate a larger threat on the battlefield that your opponents must deal with immediately
Not being able to use it to defend himself however makes Ral hard to safely play which is one of the main things you look for in good planeswalkers